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In the present investigation Calcium content was estimated from January 2013 to December 2013 at site A and site B and expressed as mg/L. Calcium was maximum in March (60.1 mg/L) and minimum in December (24.0 mg/L) from site A and Calcium was maximum in March (57.7 mg/L) and minimum in November (24.0 mg/L) from site B. during study both the sites have good calcium concentration having good results for pearl culture. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is one of the most common malignancies of the digestive system worldwide with the incidence has being increased significantly over the past three decades. CRC could present as sporadic (70%), more than half (55%) of all CRCs are attributable to lifestyle factors, including an unhealthy diet. Some studies refer higher circulating vitamin D ( 25(OH)D )was related to a statistically significant, substantially lower colorectal cancer risk, and other studies proposed the total calcium intake was inversely associated with the risk of developing colorectal cancer and other studies showed high total oxidant status ( TOS) are involved in the occurrence and development of malignant tumors. This study aims to investigate the change in the levels of calcium, vitamin D and total oxidant status levels in colorectal Patients. The results showed significance increased in total oxidant status in colorectal cancer patients but not for benign tumor and healthy peoples. Calcium levels were within the ideal limits for all groups and had not relationship with colorectal cancer. While vitamin D levels were below the normal level for all groups and Vitamin D levels was lower in the colorectal cancer group. Found inverse relationship between vitamin D levels and total oxidant status. [ABSTRACT FROM AUTHOR]

Understanding serum dynamic patterns of P, Ca, and P-Ca metabolism related hormones would help us in developing feeding strategies that can be used to reduce dietary inorganic P input and decrease P excretion in laying hens. In the current study, Hy-Line Brown laying hens (35-wk-old, n = 15) were fed with a corn–soybean meal-based commercial laying hen diet containing 0.24% non-phytate P, 3.59% Ca, 2,040 IU/kg vitamin D3, 2,500 FTU/kg phytase, 2,636 kcal/kg ME, and 15.9% crude protein. Blood samples from each laying hen were collected immediately after the first oviposition; 3, 6, 9, 12, 15, 18, and 21 h after the first oviposition; and immediately after the second oviposition. As a result, after the first oviposition, serum P and Ca levels of the laying hens were gradually increased, peaked in 6 h, and then gradually decreased all the way down until the second oviposition. Similarly, serum fibroblast growth factor 23 (FGF-23) level was gradually increased after the first oviposition, but peaked in 9 h, and then gradually decreased all the way down until the second oviposition. Serum 1,25-dihydroxy-cholecalciferol [1,25(OD)2D3] level was linearly and quadratically decreased during the egg laying cycle we observed. The serum levels of parathyroid hormone, calcitonin, and alkaline phosphatase were erratically fluctuated during the egg laying cycle in patterns that are very different from that of serum P, Ca, FGF-23, and 1,25(OD)2D3. In conclusion, the result that serum FGF-23 peaked after serum P indicates that the dynamics in serum FGF-23 levels might be driven by serum P levels during the egg laying cycle. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of phytase and dietary Ca level on performance, phytate (inositol hexa-phosphate, IP6) concentration, and anti-oxidant enzyme activity in broilers exposed to cycling high environmental temperatures. A total of 2,970 day-old Cobb 400 male broilers were randomly allocated among 6 treatments, with 15 replicate pens, and 33 birds per pen. Corn-soy diets low in available phosphorus (avP, 0.15% matrix applied) were fed in 2 phases; starter (0 to 21 d) and grower (22 to 42 d). Diets were factorially arranged by 2 × 3, with adequate (0.90% starter, 0.80% grower) or low (0.60% starter, 0.50% grower) dietary Ca and phytase (0, 500, or 3,000 phytase units (FTU)/kg). Temperature was not regulated, but followed environmental changes determined by the summer season in India; 22 to 39°C in the morning and 23 to 40°C at night. At 42 d of age, supplementing either dose of phytase increased (P < 0.001) weight gain (+128 g) and feed intake (+194 g) of birds, while only 3,000 FTU/kg phytase lowered (P < 0.01) feed conversion ratio (FCR) compared to the control. Birds fed low Ca diets had poorer (P < 0.01) weight gain (-33 g) and FCR (+0.04) than birds fed adequate Ca levels, suggesting that Ca was limiting in these diets. Phytase and low dietary Ca reduced the concentration of IP esters in the gastrointestinal tract of broilers. Lower IP6, IP5, IP4, and IP3 concentrations and increased myo-inositol provision was positively correlated to anti-oxidant enzyme activity in tissues. These results indicate that phytase can be used to alleviate the negative performance traits accredited to broilers under high temperature stress, potentially by reducing the anti-nutritive effect of IP6 and improving anti-oxidant status of birds. However, caution should be taken when reducing dietary Ca levels as improvements in IP6 degradation and anti-oxidant status cannot overcome the constraints on growth by diets that do not meet the Ca requirements. [ABSTRACT FROM AUTHOR]

Highlights • Supplementary Ca can reduce cracking & increase quality - but results are variable. • Lack of Ca uptake by fruit may be the bottleneck in the Ca response. • Little is known of the mechanisms & pathways for Ca penetration of fruit skins. • Supplementary Ca has potential to reduce cracking and extend postharvest quality. Abstract Growing interest in the commercial production of sweet cherries around the world has stimulated research on the potential for supplementary applications of calcium (Ca) as a way to mitigate the risk of catastrophic crop loss, to improve fruit quality at harvest and to extend postharvest shelf life. The objective of this review is to summarize current information, to identify knowledge gaps and to help define future research needs. We focus on (1) analysis and uptake of Ca, (2) Ca effects on rain cracking and (3) Ca effects on postharvest quality. Preharvest Ca sprays and postharvest Ca dips sometimes increase fruit Ca levels; but at other times these are ineffective. Similarly, Ca applications by overhead sprinkling during rain or by spraying or by immersion, sometimes reduce rain cracking; but not always. Reduced fruit cracking is usually accounted for as due to improvements in the mechanical properties of the skin - the fruits structural backbone. Calculation shows that osmotic effects of Ca that reduce fruit water uptake are an unlikely explanation. Preharvest or postharvest applications of Ca may also improve fruit firmness, decrease pedicel shriveling and reduce the incidence of fruit rots. The studies reviewed indicate that (1) little is known about the mechanisms and pathways of Ca uptake into the fruit and (2) Ca applications have the potential to reduce cracking and to help retain postharvest quality; but these looked-for effects are often illusive. The lack of consistent behavior is likely due to erratic movement of the polar Ca ion through the cuticle. Future studies should focus on the mechanisms and pathways of Ca penetration into developing sweet cherry fruit and on its final location at both tissue and cellular levels. [ABSTRACT FROM AUTHOR]

Abstract Cloning into a pET 11a vector, followed by high-level expression of the cold adapted subtilase, VPR, utilizing the rhamnose titratable T7 system of Lemo21, resulted in a dramatic increase of soluble protein compared to the older system used. Expression optimization clearly shows the importance of calcium in the medium after induction, both for stability of the proteinase and cell health. Characterization of the purified enzyme obtained in a redesigned purification protocol which removed apparent RNA contaminants, resulted in a significantly higher value for k cat than previously reported. The new recombinant protein exhibited slightly lower stability against thermal denaturation and thermal inactivation. Our results also indicate that two of the calcium binding sites have apparent binding constants in the mM range. Binding of calcium to the weaker of those two sites only affects resistance of the enzyme against irreversible thermal inactivation. Differential scanning calorimetry revealed a non-two-state denaturation process, with indication of presence of intermediates caused by unfolding of calcium binding motifs. Highlights • Expression of VPR enhanced by using titratable T7 system in the presence of calcium. • Improved purification, removing RNA, resulted in redefinition of enzyme properties. • Under experimental conditions VPR has two weakly bound calcium ions. • DSC reveals a non-two state unfolding process, effected by calcium in the mM range. [ABSTRACT FROM AUTHOR]

Abstract β-Hydroxy-β-methylbutyrate (HMB) is a leucine metabolite available in calcium salt (CaHMB) and free acid forms as a sports nutrition ergogenic aid. HMB has also been used to support muscle health in the elderly and other populations needing to maintain muscle mass. Several human studies have reported safety data for CaHMB, and rodent sub-chronic toxicity studies have been conducted; however, there are no published genotoxicity studies for HMB. Therefore, three studies (a bacterial reverse mutation test, an in vitro mammalian chromosomal aberration test, and an in vivo mammalian cell micronucleus test) were performed. In the Ames test, no changes in revertant colonies or background were noted with CaHMB concentrations up to 5000 μg per plate, either with or without metabolic activation in five bacterial strains. In the chromosomal aberration test, the number of aberrations associated with up to 2.5 mM CaHMB (long-term) or 10.0 mM (short-term) were similar to those observed for negative controls (<5%), and no polyploidy was observed. Lastly, in the mammalian micronucleus test, no changes in immature erythrocyte or micronuclei frequencies were observed in animals treated with up to 2000 mg·kg−1 body weight CaHMB. In conclusion, CaHMB was determined to have no genotoxic effects. Highlights • Calcium β-hydroxy β-methylbutyrate does not cause an increase in revertant bacteria in the Ames test. • Calcium β-hydroxy-β-methylbutyrate does not induce chromosomal aberrations or polyploidy in mammalian chromosomes. • Calcium β-hydroxy-β-methylbutyrate does not alter immature erythrocyte or micronuclei frequencies in mammalian cells. • Calcium β-hydroxy-β-methylbutyrate was not determined to be genotoxic using three standard test protocols. [ABSTRACT FROM AUTHOR]

Titanium and its alloys have been widely used in dental and orthopedic implants. Owing to the biotribocorrosion behavior of implants in simulated oral environment, Ti(IV) ions could be released into surrounding tissues. Current studies have found that Ti(IV) ions could affect the biological activities of immune cells in adjacent tissues and subsequently jeopardize the long-term performance of implant prostheses. However, the potential mechanism underlying its immunomodulatory properties remains unclear. Calcium signaling has been confirmed to be involved in regulation of lymphocyte immune function. Therefore, we hypothesize that Ti(IV) ions modulated T cell function through the change of intracellular calcium concentrations. This study is aimed at exploring the role of intracellular calcium responses in the modulatory effect of Ti(IV) ions on unactivated and phytohemagglutinin-activated Jurkat T cells. Here, we confirmed that Ti(IV) ions within a certain concentration range induced CD69 expression on both unactivated and activated T cells in our study. Additionally, the combined stimulation with Ti(IV) ions and PHA increased expression of IL-1β, TNF-α, and RANKL. Furthermore, we found that treatment with Ti(IV) induced a transitory increase in the levels of [Ca2+]i in activated Jurkat cells, dependent on the presence of exogenous calcium. Treatment with different doses of Ti(IV) for 24 h significantly increased the levels of [Ca2+]i in the activated Jurkat cells in a dose-dependent manner, but had little effect in the unactivated cells. Treatment with Ti(IV) did not significantly affect the PLCγ1 activation and inositol-1,4,5-trisphosphate (IP3) secretion in Jurkat cells. Taken together, these data indicated that Ti(IV) enhanced calcium influx during the T cell activation, independent of IP3-mediated intracellular calcium release. Our work provides insights into the mechanism involved in the regulation of lymphocyte behaviors under the effect of Ti(IV) ions, which may help to develop therapeutic strategies for dental implant failures. [ABSTRACT FROM AUTHOR]

Background and Purpose: Strontium ranelate, a drug approved and until recently used for the treatment of osteoporosis, mediates its effects on bone at least in part via the calcium‐sensing (CaS) receptor. However, it is not known whether bone‐targeted CaS receptor positive allosteric modulators (PAMs; calcimimetics) represent an alternative (or adjunctive) therapy to strontium (Sr2+o). Experimental Approach We assessed three structurally distinct calcimimetics [cinacalcet, AC‐265347 and a benzothiazole tri‐substituted urea (BTU‐compound 13)], alone and in combination with extracellular calcium (Ca2+o) or Sr2+o, in G protein‐dependent signalling assays and trafficking experiments in HEK293 cells and their effects on cell differentiation, tartrate‐resistant acid phosphatase (TRAP) activity and hydroxyapatite resorption assays in human blood‐derived osteoclasts. Key Results: Sr2+o activated CaS receptor‐dependent signalling in HEK293 cells in a similar manner to Ca2+o, and inhibited the maturation, TRAP expression and hydroxyapatite resorption capacity of human osteoclasts. Calcimimetics potentiated Ca2+o‐ and Sr2+o‐mediated CaS receptor signalling in HEK293 cells with distinct biased profiles, and only cinacalcet chaperoned an endoplasmic reticulum‐retained CaS mutant receptor to the cell surface in HEK293 cells, indicative of a conformational state different from that engendered by AC‐265347 and BTU‐compound 13. Intriguingly, only cinacalcet modulated human osteoclast function, reducing TRAP activity and profoundly inhibiting resorption. Conclusion and Implications: Although AC‐265347 and BTU‐compound 13 potentiated Ca2+o‐ and Sr2+o‐induced CaS receptor activation, they neither replicated nor potentiated the ability of Sr2+o to inhibit human osteoclast function. In contrast, the FDA‐approved calcimimetic, cinacalcet, inhibited osteoclast TRAP activity and hydroxyapatite resorption, which may contribute to its clinical effects on bone mineral density Linked Articles: This article is part of a themed section on Molecular Pharmacology of GPCRs. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.21/issuetoc [ABSTRACT FROM AUTHOR]

Abstract This study aimed to develop predictive models to assess the growth response of Pencillium paneum LMQA-002 and Paecilomyces variotii LMQA-001 in wholemeal multigrain bread regarding moisture, pH, calcium propionate, temperature and time of storage. A complete factorial design was performed using slices of bread with different formulation: moisture (36; 38; 40; 42%), pH (5.1; 5.3; 5.5) and calcium propionate (0.6; 0.8 and 1%). The slices were inoculated with 102-103 spores following storage at 20 °C, 25 °C and 30 °C for up to 21 days. The degree of agreement between predictions and observations was >90% for both species. According to the results, the growth of P. paneum LMQA-002 and P. variotii LMQA-001 was inhibited for up to 21 days in bread formulations presenting pH (5.1), 36% moisture and 0.6% calcium propionate. The lower temperatures (20 °C and 25 °C) contributed to the growth of P. paneum LMQA-002 and storage at 30 °C favored the growth of P. variotii LMQA-001. Validation results showed correct predictions in 80% of the cases. A significant achievement of this study comprises the extension of wholemeal multigrain bread shelf-life from 12 to 21 days (>70% increase). Graphical abstract Image 1 Highlights • The responses of P. paneum and P. variotii in wholemeal breads have been assessed. • The effect of pH, calcium propionate, moisture and storage temperature were studied. • Both fungi were inhibited by reducing the moisture, pH and calcium propionate. • The predicted models were validated and predicted correctly in 80% of the cases. [ABSTRACT FROM AUTHOR]

Using the patch-clamp method in the whole-cell configuration, we showed that the new derivatives of 2-aminothiophene-3-carboxylic acid, which were synthesized by us earlier, can both block (compound 1) and potentiate (compound 2) calcium-activated chloride currents in single rat cerebellar Purkinje cells. [ABSTRACT FROM AUTHOR]

The present study is to investigate the reason why the ceratohyal cartilage (CH) angle of zebrafish larvae were larger compared to the control group after their female parents were treated with cadmium (F-Cd). However, the CH angle was smaller compared to the control group when embryos were directly exposed to Cd 2+ for 72 h (D-Cd). Results showed that calcium contents of larvae were lower than the control, but the transporter isoforms trpv4 and trpv6 mRNA expressions were significantly increased upon D-Cd treatment. Furthermore, external Ca 2+ added during D-Cd treatment reveals that the CH angles of larvae did not appear significantly different compared to the control. On the other hand, E2 (17β-estradiol) contents were higher around 1.9 folds in the ovaries of females; CH angle were over 25°, and Cd 2+ contents were higher around 6 folds than the control group on larvae treated through F-Cd treatment; CH angles and E2 levels on larvae were higher than the control after the larvae were treated with 1.84 μM E2 (D-E2); Estradiol receptor (ER) isoforms ERβ1 and ERα mRNA expressions significantly increased when 0 hpf embryos were either treated with D-E2 or D-Cd. According to the results, we suggested that the CH angle of larvae become larger upon F-Cd treatment due to maternal Cd 2+ inducing E2 levels. However, the CH angle of larvae appeared to be smaller compared to the control upon D-Cd treatment. We suggested that the CH angle decreased due to the decrease of Ca 2+ contents upon Cd 2+ exposure. [ABSTRACT FROM AUTHOR]

Calcium ions (Ca2+) play an important role in the toxicity of the cysteine-rich and cationic antifungal protein PAF from Penicillium chrysogenum: high extracellular Ca2+ levels reduce the toxicity of PAF in the sensitive model fungus Neurospora crassa in a concentration dependent way. However, little is known about the mechanistic details of the Ca2+ ion impact and the Ca2+ binding capabilities of PAF outside the fungal cell, which might be the reason for the activity loss. Using nuclear magnetic resonance (NMR), isothermal titration calorimetry and molecular dynamics (MD) simulations we demonstrated that PAF weakly, but specifically binds Ca2+ ions. MD simulations of PAF predicted one major Ca2+ binding site at the C-terminus involving Asp53 and Asp55, while Asp19 was considered as putative Ca2+ binding site. The exchange of Asp19 to serine had little impact on the Ca2+ binding, however caused the loss of antifungal activity, as was shown in our recent study. Now we replaced the C-terminal aspartates and expressed the serine variant PAFD53S/D55S. The specific Ca2+ binding affinity of PAFD53S/D55S decreased significantly if compared to PAF, whereas the antifungal activity was retained. To understand more details of Ca2+ interactions, we investigated the NMR and MD structure/dynamics of the free and Ca2+-bound PAF and PAFD53S/D55S. Though we found some differences between these protein variants and the Ca2+ complexes, these effects cannot explain the observed Ca2+ influence. In conclusion, PAF binds Ca2+ ions selectively at the C-terminus; however, this Ca2+ binding does not seem to play a direct role in the previously documented modulation of the antifungal activity of PAF. [ABSTRACT FROM AUTHOR]

Experiments have shown that the relaxation phase of cardiac sarcomeres during an isometric twitch is prolonged in muscles that reached a higher peak tension. However, the mechanism is not completely understood. We hypothesize that the binding of calcium to troponin is enhanced by the tension in the thin filament, thus contributing to the prolongation of contraction upon higher peak tension generation. To test this hypothesis, we developed a computational model of sarcomere mechanics that incorporates tension-dependence of calcium binding. The model was used to simulate isometric twitch experiments with time dependency in the form of a two-state cross-bridge cycle model and a transient intracellular calcium concentration. In the simulations, peak isometric twitch tension appeared to increase linearly by 51.1 KPa with sarcomere length from 1.9 μm to 2.2 μm. Experiments showed an increase of 47.3 KPa over the same range of sarcomere lengths. The duration of the twitch also increased with both sarcomere length and peak intracellular calcium concentration, likely to be induced by the inherently coupled increase of the peak tension in the thin filament. In the model simulations, the time to 50% relaxation (tR50) increased over the range of sarcomere lengths from 1.9 μm to 2.2 μm by 0.11s, comparable to the increased duration of 0.12s shown in experiments. Model simulated tR50 increased by 0.12s over the range of peak intracellular calcium concentrations from 0.87 μM to 1.45 μM. Our simulation results suggest that the prolongation of contraction at higher tension is a result of the tighter binding of Ca2+ to troponin in areas under higher tension, thus delaying the deactivation of the troponin. [ABSTRACT FROM AUTHOR]

The calcium sensing receptor (CaSR) in the distal nephron decreases the propensity for calcium stones. Here we investigate if the apical CaSR in the proximal tubule also prevents stone formation acting via regulation of apical dicarboxylate and citrate transport. Urinary citrate, partially reabsorbed as a dicarboxylate in the proximal tubule lumen, inhibits stone formation by complexing calcium. We previously demonstrated a novel apical calcium-sensitive dicarboxylate transport system in OK proximal tubule cells. This calcium-sensitive process has the potential to modulate the amount of citrate available to complex increased urinary calcium. Using isotope labeled succinate uptake in OK cells along with various pharmacologic tools we examined whether the CaSR alters apical dicarboxylate transport and through which signal transduction pathways this occurs. Our results indicate that in the proximal tubule CaSR adjusts apical dicarboxylate transport, and does so via a CaSR → Gq → PKC signaling pathway. Thus, the CaSR may decrease the propensity for stone formation via actions in both proximal and distal nephron segments. [ABSTRACT FROM AUTHOR]

The present study was performed to determine the molecular mechanism of calcium gluconate (CG) in alleviating the toxic effect of hydrofluoric (HF) acid on human dermal fibroblasts (HDFs). HDF morphology was observed by optical microscopy and the vimentin immunofluorescence assay. Cell viability and apoptosis were evaluated by the Cell Counting Kit‑8 and Annexin V/propidium iodide assays, respectively. The levels of apoptosis‑associated factors, as well as Wnt2, Wnt3a and β‑catenin were detected by reverse transcription‑quantitative polymerase chain reaction and western blotting. Levels of matrix metalloproteinase (MMP)‑1 and basic fibroblast growth factor (bFGF) were detected by ELISA and western blotting. Carboxyterminal propeptide of type Ⅰ collagen (CICP) was detected by ELISA, while L‑Hydroxyproline (L‑HYP) was detected by colorimetry. First, the morphology of normal HDFs was observed. Cell viability was inhibited and apoptosis was increased in a doseand time‑dependent manner following treatment with HF acid [0, 2, 4, 6, 8, 10 and 20% (v/v)] for 0, 2, 4, 6, 8, 10 and 20 min. The effects were blocked by CG at different doses (50, 100 and 200 μmol/l) and time points (6, 12 and 24 h), following treatment with 8% (v/v) HF acid for 6 min. The levels of Caspase‑3, B‑cell lymphoma (Bcl)‑2 associated X protein, Wnt2, Wnt3a and β‑catenin were decreased, whereas Bcl‑2 was increased by CG treatment dose‑dependently, when compared with HF control. CG promoted the expression of MMP‑1, bFGF and L‑HYP, and inhibited CICP, when compared with HF control. Based on the present results, CG alleviated the toxic effect of HF acid on HDFs by regulating the Wnt/β‑catenin signaling pathway. [ABSTRACT FROM AUTHOR]

Four molecular weights of poly- l -lysine (PLL) [1000–5000 Da, 1500–8000 Da, 4000–15,000 Da and 15,000–30,000 Da] and three molecular weights of polyethyleneimine (PEI) [800 Da, 2,000 Da, and 25,000 Da] were used to systematically study the effect of calcium (Ca 2+ ) to improve transfection efficiency of polyelectrolyte complexes. Complexes made using different molecular weights of PLL or PEI polymer showed clear differences in the levels of gene expression in the presence and absence of calcium chloride when tested using A549 human lung carcinoma cells. Complexes formed from PLL or PEI 800 Da were exhibited negligible expression of pDNA according to a luciferase reporter assay. Low molecular weight PLL and PEI 800 Da, however, became highly efficient gene delivery vehicles when calcium was added to the nascent complexes while maintaining the low cytotoxicity of low molecular weight polyamines. Additional analyses indicated that the most effective formulations utilized a threshold level of calcium, which created small, stable particles, but also facilitated unpackaging of the gene complexes and release of pDNA. [ABSTRACT FROM AUTHOR]

The stick insect is a well-established experimental animal to study the neural basis of walking. Here, we introduce a preparation that allows combining calcium imaging in efferent neurons with electrophysiological recordings of motor neuron activity in the stick insect thoracic nerve cord. The intracellular free calcium concentration in middle leg retractor coxae motor neurons and modulatory octopaminergic DUM neurons was monitored after backfilling lateral nerve nl5 that contains the axons of these neurons with the calcium indicator Oregon Green BAPTA-1. Rhythmic spike activity in retractor and protractor motor neurons was evoked by pharmacological activation of central pattern generating neuronal networks and recorded extracellularly from lateral nerves. A primary goal of this study was to investigate whether changes in the intracellular free calcium concentration observed in motor neurons during oscillatory activity depend on action potentials. We show that rhythmic spike activity in leg motor neurons induced either pharmacologically or by tactile stimulation of the animal is accompanied by a synchronous modulation in the intracellular free calcium concentration. Calcium oscillations in motor neurons do not appear to depend on calcium influx through voltage-sensitive calcium channels that are gated by action potentials because Calcium oscillations persist after pharmacologically blocking action potentials in the motor neurons. Calcium oscillations were also apparent in the modulatory DUM neurons innervating the same leg muscle. However, the timing of calcium oscillations varied not only between DUM neurons and motor neurons, but also among different DUM neurons. Therefore, we conclude that the motor neurons and the different DUM neurons receive independent central drive. [ABSTRACT FROM AUTHOR]

An experiment was conducted using non-colostomized and colostomized broiler breeder hens to determine the effects of feeding limestone of 2 different mean particle sizes (185 microns and 3490 microns) on P excretion, total P and Ca retention, and urinary P and Ca excretion during a 6-week feeding study. Additionally, changes in plasma inorganic P (iP) and ionic Ca (Ca++) and urinary excretion of P and Ca were determined in one egg laying cycle of 24 hours. One-hundred-fifty non-colostomized and 6 colostomized broiler breeder hens, 30 wk of age, were divided into 2 groups and fed broiler breeder diets supplemented with either small particle or large particle limestone. Two % acid insoluble ash (Celite) was added to the feed as a marker. Diets, excreta, and urine samples were analyzed for total P and Ca by ionic coupling plasma (ICP) analysis. The non-colostomized breeders fed large particle limestone compared to small limestone particles produced a significant increase in percent tibia ash (P < 0.0001) and egg specific gravity (P = 0.0382), but P excretion approached a tendency of being reduced (P = 0.1585). The urinary total P and Ca (∼18 and 9%, respectively) of total P and Ca excretion for breeders fed both sizes of limestone was not significantly different in the colostomized breeders. In plasma, both iP and Ca++ reached a peak during 18 to 20 h and 20 to 24 h post oviposition for smaller and larger particle sized limestone fed groups, respectively. The maximal excretion of urinary P was found during 11 to 20 h post oviposition, whereas urinary Ca peaked during 0 to 11 h post oviposition for both smaller and larger particle sized limestone supplemented groups. In summary, the findings indicate that the particle size (smaller and larger) of calcium source did not significantly influence the quantitative total urinary excretion of Ca and P but did influence the timing of Ca and P excretion. [ABSTRACT FROM AUTHOR]

Key points: Cigarette smoke components directly alter muscle fatigue resistance and intracellular muscle fibre Ca2+ handling independent of a change in lung structure. Changes in muscle vascular structure are associated with a depletion of satellite cells. Sarcoplasmic reticulum Ca2+ uptake is substantially impaired in myofibres during fatiguing contractions in mice treated with cigarette smoke extract. Abstract: Cigarette smokers exhibit exercise intolerance before a decline in respiratory function. In the present study, the direct effects of cigarette smoke on limb muscle function were tested by comparing cigarette smoke delivered to mice by weekly injections of cigarette smoke extract (CSE), or nose‐only exposure (CS) 5 days each week, for 8 weeks. Cigarette smoke delivered by either route did not alter pulmonary airspace size. Muscle fatigue measured in situ was 50% lower in the CSE and CS groups than in control. This was accompanied by 34% and 22% decreases in soleus capillary‐to‐fibre ratio of the CSE and CS groups, respectively, and a trend for fewer skeletal muscle actin‐positive arterioles (P = 0.07). In addition, fewer quiescent satellite cells (Nes+Pax7+) were associated with soleus fibres in mice with skeletal myofibre VEGF gene deletion (decreased 47%) and CS exposed (decreased 73%) than with control fibres. Contractile properties of isolated extensor digitorum longus and soleus muscles were impaired. In flexor digitorum brevis myofibres isolated from CSE mice, fatigue resistance was diminished by 43% compared to control and CS myofibres, and this was accompanied by a pronounced slowing in relaxation, an increase in intracellular Ca2+ accumulation, and a slowing in sarcoplasmic reticulum Ca2+ uptake. These data suggest that cigarette smoke components may impair hindlimb muscle vascular structure, fatigue resistance and myofibre calcium handling, and these changes ultimately affect contractile efficiency of locomotor muscles independent of a change in lung function. [ABSTRACT FROM AUTHOR]

Abstract: Nicotinic acid adenine dinucleotide phosphate (NAADP) is currently the most potent endogenous Ca2+ mobilizing second messenger. Upon specific extracellular stimulation, rapid production of NAADP has been observed in different cell types from sea urchin eggs to mammalian cells. More than 20 years after the discovery of NAADP, there is still controversy surrounding its metabolism and target receptors/ion channels and organelles. This article briefly reviews recent developments in the NAADP field. Besides the metabolism of NAADP, this review focuses on assumed organelles and putative targets, e.g. ion channels, with special emphasis on ryanodine receptor type 1 (RyR1) and two‐pore channels (TPCs). The role of NAADP as a Ca2+ trigger is also discussed and the importance of NAADP in the formation of initial Ca2+ microdomains is highlighted. [ABSTRACT FROM AUTHOR]

Abstract: Discovery of the STIM1 and Orai proteins as the principal components of store‐operated Ca2+ entry has drawn attention to contact sites between the endoplasmic reticulum (ER) and the plasma membrane (PM). Such contacts between adjacent membranes of different cellular organelles, primarily between the mitochondria and the ER, had already been known as the sites where Ca2+ released from the ER can be efficiently channelled to the mitochondria and also where phosphatidylserine synthesis and transfer takes place. Recent studies have identified contact sites between virtually every organelle and the ER and the functional importance of these small specialized membrane domains is increasingly recognized. Most recent developments have highlighted the role of phosphatidylinositol 4‐phosphate gradients as critical determinants of the non‐vesicular transport of various lipids from the ER to other organelles such as the Golgi or PM. As we learn more about membrane contact sites it becomes apparent that Ca2+ is not only transported at these sites but also controls both the dynamics and the lipid transfer efficiency of these processes. Conversely, lipids are critical for regulating the Ca2+ entry process. This review will summarize some of the most exciting recent developments in this rapidly expanding research field. [ABSTRACT FROM AUTHOR]

Calcium (Ca2+) ions are prominent cell signaling regulators that carry information for a variety of cellular processes and are critical for neuronal survival and function. Furthermore, Ca2+ acts as a prominent second messenger that modulates divergent intracellular cascades in the nerve cells. Therefore, nerve cells have developed intricate Ca2+ signaling pathways to couple the Ca2+ signal to their biochemical machinery. Notably, intracellular Ca2+ homeostasis greatly relies on the rapid redistribution of Ca2+ ions into the diverse subcellular organelles which serve as Ca2+ stores, including the endoplasmic reticulum (ER). It is well established that Ca2+ released into the neuronal cytoplasm is pumped back into the ER by the sarco-/ER Ca2+ ATPase 2 (SERCA2), a P-type ion-motive ATPase that resides on the ER membrane. Even though the SERCA2 is constitutively expressed in nerve cells, its precise role in brain physiology and pathophysiology is not well-characterized. Intriguingly, SERCA2-dependent Ca2+ dysregulation has been implicated in several disorders that affect cognitive function, including Darier’s disease, schizophrenia, Alzheimer’s disease, and cerebral ischemia. The current review summarizes knowledge on the expression pattern of the different SERCA2 isoforms in the nervous system, and further discusses evidence of SERCA2 dysregulation in various neuropsychiatric disorders. To the best of our knowledge, this is the first literature review that specifically highlights the critical role of the SERCA2 in the brain. Advancing knowledge on the role of SERCA2 in maintaining neuronal Ca2+ homeostasis may ultimately lead to the development of safer and more effective pharmacotherapies to combat debilitating neuropsychiatric disorders. [ABSTRACT FROM AUTHOR]

Background: Phaleria macrocarpa (PM) has been used conventionally to cure hypertension. Objective: The objective of the study is to determine the active fraction and its chemical composition responsible for antihypertensive activity of PM fruit using a bioactivity-guided investigation on different extracts of the fruit. Materials and Methods: Among the extracts of PM, water extract (WE) showed prominent effect in screening test by inhibiting noninvasive blood pressure (BP) in spontaneously hypertensive rats (SHRs). WE was investigated further using hypertensive and normotensive experimental models. Results: WE caused dose-dependent hypotensive effect in normotensive rats with adrenergic and cholinergic effects by inhibiting the elevated levels of norepinephrine hydrochloride and acetylcholine hydrochloride induced mean arterial pressure (MAP) and heart rate (HR). In addition, WE enhanced the activity of nonselective β-agonist isoprenaline on MAP and inhibited the increased HR. Similarly, WE demonstrated significant inhibition on pulse wave velocity (PWV), MAP, and HR in SHRs. Fractions of WE were tested for vasorelaxation effect on rat aortic explant. Among the fractions, water fraction-4 (PF-4) showed pronounced effects. Column chromatography of PF-4 yielded two subfractions; among them, sub-fraction-2 (SF-2) displayed significant vasorelaxation effect in endothelium-denuded and endothelium-intact aortas. Further, SF-2 revealed significant inhibition in calcium influx and mobilization from intracellular stores. Gas chromatography-mass spectroscopy analysis of SF-2 revealed abundance of kaempferol 3-O-β glucuronide, mangiferin, gallic acid, and rutin. Conclusions: This study demonstrates that polar phytochemical fraction of PM fruit has a promising potential of reducing PWV, BP, and HR. This antihypertensive effect is probably due to the inhibition of arterial tone and extracellular calcium influx. Abbreviations used: WE: Water extract; SHRs: Spontaneously hypertensive rats; NE-HCl: Norepinephrine hydrochloride; MAP: Mean arterial pressure; HR: Heart rate. [ABSTRACT FROM AUTHOR]

In adult bone injuries, periosteum-derived mesenchymal stem/stromal cells (MSCs) form bone via endochondral ossification (EO), whereas those from bone marrow (BM)/endosteum form bone primarily through intramembranous ossification (IMO). We hypothesized that this phenomenon is influenced by the proximity of MSCs residing in the BM to the trabecular bone microenvironment. Herein, we investigated the impact of the bone mineral phase on human BM-derived MSCs' choice of ossification pathway, using a biomimetic bone-like hydroxyapatite (BBHAp) interface. BBHAp induced hyperstimulation of extracellular calcium-sensing receptor (CaSR) and temporal down-regulation of parathyroid hormone 1 receptor (PTH1R), leading to inhibition of chondrogenic differentiation of MSCs even in the presence of chondroinductive factors, such as transforming growth factor-β1 (TGF-β1). Interestingly rescuing PTH1R expression using human PTH fragment (1-34) partially restored chondrogenesis in the BBHAp environment. In vivo studies in an ectopic site revealed that the BBHAp interface inhibits EO and strictly promotes IMO. Furthermore, CaSR knockdown (CaSR KD) disrupted the bone-forming potential of MSCs irrespective of the absence or presence of the BBHAp interface. Our findings confirm the expression of CaSR in human BM-derived MSCs and unravel a prominent role for the interplay between CaSR and PTH1R in regulating MSC fate and the choice of pathway for bone formation. [ABSTRACT FROM AUTHOR]

Calcium homeostasis is essential for maintaining the viability and function of pancreatic β cells and plays a key role in preventing the development of diabetes. Decreased levels of ATPase sarcoplasmic/endoplasmic reticulum Ca2+-transporting 2 (ATP2a2), the main calcium pump in β cells, are often found in individuals with diabetes and in diabetic animal models. However, the regulators of ATP2a2 and the molecular mechanisms responsible for controlling ATP2a2 activity remain unclear. Etoposide-induced protein 2.4 (Ei24) is also down-regulated in β cells of diabetic individuals, whereas the effect of decreased Ei24 level on β-cell function is not clarified. Here, using Cre-LoxP and CRISPR/Cas9-based genomic knockout (KO) approaches to generate pancreatic β cell–specific Ei24 KO mice and pancreatic β-cell lines, we found that Ei24 regulates ATP2a2 activity. Specifically, we observed that Ei24 binds to ATP2a2 through Ei24 residues 293–299, which we named here the ATP2a2-interacting region (AIR). Loss of Ei24 inactivated ATP2a2, disrupted calcium homeostasis, and deactivated the calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2)–AMP-activated protein kinase (AMPK) pathway. Elevation of calcium concentration in the endoplasmic reticulum or agonist-induced AMPK activation rescued pancreatic β-cell survival and improved glucose tolerance of Ei24 KO mice. Our findings indicate that targeting the Ei24–ATP2a2 interaction to increase ATP2a2 activity can protect pancreatic β cells and improve glucose homeostasis in diabetic models, suggesting that Ei24 could potentially serve as a target to prevent or manage diabetes. [ABSTRACT FROM AUTHOR]

Face to the limited repair capability of cartilage, we intended to find out signaling responsible for its matrix synthesis. Since spontaneous calcium response likes a label of cell status, here it was mapped in fresh and 24 hr cultured in situ chondrocytes under oxygen tensions of 20%, 5%, and 1% as well as mimic hypoxia conditions. The calcium source was traced using ethylene glycol‐bis (β‐aminoethyl ether)‐N,N,N′,N′‐tetraacetic acid (EGTA) and thapsigargin (TG) to treat cartilage. Their relative matrix of type II collagen (COLL‐II) and glycosaminoglycan (GAG) were quantified after cultured for 3 and 7 days. We disclosed the specific fingerprint of calcium response and matrix deposition along the histological zones under various oxygen tensions, from which the effects of hyperoxia, normoxia, and hypoxia conditions on as well as the optimal oxygen tensions for maintenance of various zones of cartilage or chondrocytes were derived and obtained. Our results revealed that cytoplasm calcium was conducive to synthesize COLL‐II but detrimental to synthesize GAG. These results provide correlation in addition to details of intracellular calcium response and matrix deposition in in situ cartilage along its histological zones under physiological oxygen tensions. [ABSTRACT FROM AUTHOR]

The sperm acrosome reaction (AR), an essential event for mammalian fertilization, involves Ca2+ permeability changes leading to exocytosis of the acrosomal vesicle. The acrosome, an intracellular Ca2+ store whose luminal pH is acidic, contains hydrolytic enzymes. It is known that acrosomal pH (pHacr) increases during capacitation and this correlates with spontaneous AR. Some AR inducers increase intracellular Ca2+ concentration ([Ca2+]i) through Ca2+ release from internal stores, mainly the acrosome. Catsper, a sperm specific Ca2+ channel, has been suggested to participate in the AR. Curiously, Mibefradil and NNC55‐0396, two CatSper blockers, themselves elevate [Ca2+]i by unknown mechanisms. Here we show that these compounds, as other weak bases, can elevate pHacr, trigger Ca2+ release from the acrosome, and induce the AR in both mouse and human sperm. To our surprise, μM concentrations of NNC55‐0396 induced AR even in nominally Ca2+ free media. Our findings suggest that alkalization of the acrosome is critical step for Ca2+ release from the acrosome that leads to the acrosome reaction. [ABSTRACT FROM AUTHOR]

The Secretory Pathway Ca 2+ ATPases SPCA1 and SPCA2 transport Ca 2+ and Mn 2+ into the Golgi and Secretory Pathway. SPCA2 mediates store-independent Ca 2+ entry (SICE) via STIM1-independent activation of Orai1, inducing constitutive Ca 2+ influx in mammary epithelial cells during lactation. Here, we show that like SPCA2, also the overexpression of the ubiquitous SPCA1 induces cytosolic Ca 2+ influx, which is abolished by Orai1 knockdown and occurs independently of STIM1. This process elevates the Ca 2+ concentration in the cytosol and in the non-endoplasmic reticulum (ER) stores, pointing to a functional coupling between Orai1 and SPCA1. In agreement with this, we demonstrate via Total Internal Reflection Fluorescence microscopy that Orai1 and SPCA1a co-localize near the plasma membrane. Interestingly, SPCA1 overexpression also induces Golgi swelling, which coincides with translocation of the transcription factor TFE3 to the nucleus, a marker of Golgi stress. The induction of Golgi stress depends on a combination of SPCA1 activity and SICE, suggesting a role for the increased Ca 2+ level in the non-ER stores. Finally, we tested whether impaired SPCA1a/Orai1 coupling may be implicated in the skin disorder Hailey-Hailey disease (HHD), which is caused by SPCA1 loss-of-function. We identified HHD-associated SPCA1a mutations that impair either the Ca 2+ transport function, Orai1 activation, or both, while all mutations affect the Ca 2+ content of the non-ER stores. Thus, the functional coupling between SPCA1 and Orai1 increases cytosolic and intraluminal Ca 2+ levels, representing a novel mechanism of SICE that may be affected in HHD. [ABSTRACT FROM AUTHOR]

Differentiation of naïve CD4 + T cells into effector subtypes with distinct cytokine profiles and physiological roles is a tightly regulated process, the imbalance of which can lead to an inadequate immune response or autoimmune disease. The crucial role of Ca 2+ signals, mainly mediated by the store operated Ca 2+ entry (SOCE) in shaping the immune response is well described. However, it is unclear if human effector CD4 + T cell subsets show differential Ca 2+ signatures in response to different stimulation methods. Herein, we provide optimized in vitro culture conditions for polarization of human CD4 + effector T cells and characterize their SOCE following both pharmacological store depletion and direct T-cell receptor (TCR) activation. Moreover, we measured whole cell Ca 2+ release activated Ca 2+ currents (I CRAC ) and investigated whether the observed differences correlate to the expression of CRAC genes. Our results show that Ca 2+ profiles of helper CD4 + Th1, Th2 and Th17 are distinct and in part shaped by the intensity of stimulation. Regulatory T cells (Treg) are unique being the subtype with the most prominent SOCE response. Analysis of in vivo differentiated Treg unraveled the role of differential expression of ORAI2 in fine-tuning signals in Treg vs. conventional CD4 + T cells. [ABSTRACT FROM AUTHOR]

Abstract We report a new NMR-scale purification procedure for two recombinant wild type fragments of the stromal interaction molecule 1 (STIM1). This protein acts as a calcium sensor in the endoplasmic reticulum (ER) and extends into the cytosol accumulating at ER – plasma membrane (PM) junctions upon calcium store depletion ultimately leading to activation of the Orai/CRAC channel. The functionally relevant cytosolic part of STIM1 consists of three coiled coil domains, which are mainly involved in intra- and inter-molecular homomeric interactions as well as coupling to and gating of CRAC channels. The optimized one-step rapid purification procedure for two 15N,13C isotope-labeled cytosolic coiled coil fragments, which avoids the problems of previous approaches. The high yields of soluble well folded 15N,13C isotope-labeled cytosolic coiled coil fragments followed by detergent screening provide for initial NMR characterization of these domains. The longer 30.5 kDa fragment represents the largest STIM1 wild type fragment that has been recombinantly prepared and characterized in solution without need for mutation or refolding. Highlights • An efficient preparation and purification protocol for coiled coil proteins is presented. • The key purification step is on-column thrombin cleavage of a GST tag. • The protocol is suitable for preparation of stable isotope labelled NMR samples. [ABSTRACT FROM AUTHOR]

The total content of ascorbic acid (AA) determined in selected Fijian foods from different food groups of cereals [long grain rice, brown rice, white bread, wholemeal bread, weet-Bix, oats and flours], pulses [yellow split, black eye beans, chickpea, green gram/moong whole, bengal gram/chana dal, spilt red gram/toor dal, blue peas, red kidney beans], poultry/meat products [chicken breast, lamb chops, fish and egg] and dairy products [milk powders and cheese] was in the range 24.54 ± 1.37 to 1.87 ± 0.69 mg/100 g. Further, the influence of AA on the bioavailability of Fe, Zn and Ca was determined using in vitro gastrointestinal digestion method by addition of (5 or 10 mg) AA in 2 g food sample. Pulses showed low content of AA whereas green leafy vegetables showed high content but AA was not detected in cereals, poultry/meat and dairy products. Our study confirmed that AA in chickpea reduced Fe bioavailability from 38.69 to 22.77% but increased in red kidney beans from 1.04 to 11.57%, in green gram (whole moong) 1.79 to 6.48% and wholemeal bread 2.44 to 8.76% whereas bioavailability of Zn and Ca was increased. [ABSTRACT FROM AUTHOR]

During the development of the early spinal circuitry in zebrafish, spontaneous Ca 2+ transients in the primary motor neurons (PMNs) are reported to transform from being slow and uncorrelated, to being rapid, synchronized and patterned. In this study, we demonstrated that in intact zebrafish, Ca 2+ release via two-pore channel type 2 (TPC2) from acidic stores/endolysosomes is required for the establishment of synchronized activity in the PMNs. Using the SAIGFF213A;UAS:GCaMP7a double-transgenic zebrafish line, Ca 2+ transients were visualized in the caudal PMNs (CaPs). TPC2 inhibition via molecular, genetic or pharmacological means attenuated the CaP Ca 2+ transients, and decreased the normal ipsilateral correlation and contralateral anti-correlation, indicating a disruption in normal spinal circuitry maturation. Furthermore, treatment with MS-222 resulted in a complete (but reversible) inhibition of the CaP Ca 2+ transients, as well as a significant decrease in the concentration of the Ca 2+ mobilizing messenger, nicotinic acid adenine diphosphate (NAADP) in whole embryo extract. Together, our new data suggest a novel function for NAADP/TPC2-mediated Ca 2+ signaling in the development, coordination, and maturation of the spinal network in zebrafish embryos. [ABSTRACT FROM AUTHOR]

Recent evidence highlights a role for sex and hormonal status in regulating cellular responses to ischemic brain injury and neurodegeneration. A key pathological event in ischemic brain injury is the opening of a mitochondrial permeability transition pore (MPT) induced by excitotoxic calcium levels, which can trigger irreversible damage to mitochondria accompanied by the release of pro-apoptotic factors. However, sex differences in brain MPT modulation have not yet been explored. Here, we show that mitochondria isolated from female mouse forebrain have a lower calcium threshold for MPT than male mitochondria, and that this sex difference depends on the MPT regulator cyclophilin D (CypD). We also demonstrate that an estrogen receptor beta (ERβ) antagonist inhibits MPT and knockout of ERβ decreases the sensitivity of mitochondria to the CypD inhibitor, cyclosporine A. These results suggest a functional relationship between ERβ and CypD in modulating brain MPT. Moreover, co-immunoprecipitation studies identify several ERβ binding partners in mitochondria. Among these, we investigate the mitochondrial ATPase as a putative site of MPT regulation by ERβ. We find that previously described interaction between the oligomycin sensitivity-conferring subunit of ATPase (OSCP) and CypD is decreased by ERβ knockout, suggesting that ERβ modulates MPT by regulating CypD interaction with OSCP. Functionally, in primary neurons and hippocampal slice cultures, modulation of ERβ has protective effects against glutamate toxicity and oxygen glucose deprivation, respectively. Taken together, these results reveal a novel pathway of brain MPT regulation by ERβ that could contribute to sex differences in ischemic brain injury and neurodegeneration. [ABSTRACT FROM AUTHOR]

The ability of the Cav1 channel inhibitor isradipine to slow the loss of substantia nigra pars compacta (SNc) dopaminergic (DA) neurons and the progression of Parkinson's disease (PD) is being tested in a phase 3 human clinical trial. But it is unclear whether and how chronic isradipine treatment will benefit SNc DA neurons in vivo. To pursue this question, isradipine was given systemically to mice at doses that achieved low nanomolar concentrations in plasma, near those achieved in patients. This treatment diminished cytosolic Ca2+ oscillations in SNc DA neurons without altering autonomous spiking or expression of Ca2+ channels, an effect mimicked by selectively knocking down expression of Cav1.3 channel subunits. Treatment also lowered mitochondrial oxidant stress, reduced a high basal rate of mitophagy, and normalized mitochondrial mass - demonstrating that Cav1 channels drive mitochondrial oxidant stress and turnover in vivo. Thus, chronic isradipine treatment remodeled SNc DA neurons in a way that should not only diminish their vulnerability to mitochondrial challenges, but to autophagic stress as well. [ABSTRACT FROM AUTHOR]

One major pathophysiological hallmark of Alzheimer's disease (AD) is senile plaques composed of amyloid β (Aβ). In the amyloidogenic pathway, cleavage of the amyloid precursor protein (APP) is shifted towards Aβ production and soluble APPβ (sAPPβ) levels. Aβ is known to impair synaptic function; however, much less is known about the physiological functions of sAPPβ. The neurotrophic properties of sAPPα, derived from the non-amyloidogenic pathway of APP cleavage, are well-established, whereas only a few, conflicting studies on sAPPβ exist. The intracellular pathways of sAPPβ are largely unknown. Since sAPPβ is generated alongside Aβ by β-secretase (BACE1) cleavage, we tested the hypothesis that sAPPβ effects differ from sAPPα effects as a neurotrophic factor. We therefore performed a head-to-head comparison of both mammalian recombinant peptides in developing primary hippocampal neurons (PHN). We found that sAPPα significantly increases axon length ( p  = 0.0002) and that both sAPPα and sAPPβ increase neurite number ( p  < 0.0001) of PHN at 7 days in culture (DIV7) but not at DIV4. Moreover, both sAPPα- and sAPPβ-treated neurons showed a higher neuritic complexity in Sholl analysis. The number of glutamatergic synapses ( p  < 0.0001), as well as layer thickness of postsynaptic densities (PSDs), were significantly increased, and GABAergic synapses decreased upon sAPP overexpression in PHN. Furthermore, we showed that sAPPα enhances ERK and CREB1 phosphorylation upon glutamate stimulation at DIV7, but not DIV4 or DIV14. These neurotrophic effects are further associated with increased glutamate sensitivity and CREB1-signaling. Finally, we found that sAPPα levels are significantly reduced in brain homogenates of AD patients compared to control subjects. Taken together, our data indicate critical stage-dependent roles of sAPPs in the developing glutamatergic system in vitro , which might help to understand deleterious consequences of altered APP shedding in AD patients, beyond Aβ pathophysiology. [ABSTRACT FROM AUTHOR]

Context: It has been shown that adipogenesis can be modulated by factors such as all-trans retinoic acid (ATRA) and calcium. Objective: To determine, the combined effect of ATRA and calcium on the differentiation of human adipose-derived stem cells (hADSCs). Methods: Mesenchymal stem cells (MSCs) were differentiated into the adipocytes by 0.5 and 1 µM of ATRA and 5 and 10 mM calcium separately or in combination. After MTS assay the differentiation of MSCs to adipocyte was evaluated, Oil Red O staining, GLUT4 concentration and gene expression of PPARG2, adiponectin, and GLUT4 were measured by Real-Time PCR. Results: Except 10 mM calcium treated group, other groups and more significantly combination treatments could reduce all adipocyte markers compared to the control. Conclusion: These results suggest that ATRA and calcium together have significant inhibitory effect on adipogenesis that can be helpful for finding new mechanisms to prevent or control the adipogenesis. [ABSTRACT FROM AUTHOR]

Mitochondria play a crucial role in neuronal function, especially in energy production, the generation of reactive oxygen species, and calcium signaling. Multiple lines of evidence have suggested the possible involvement of mitochondrial deficits in major psychiatric disorders, such as schizophrenia and bipolar disorder. This review will outline the current understanding of the physiological role of mitochondria and their dysfunction under pathological conditions, particularly in psychiatric disorders. The current knowledge about mitochondrial deficits in these disorders is somewhat limited because of the lack of effective methods to dissect dynamic changes in functional deficits that are directly associated with psychiatric conditions. Human neuronal cell model systems have been dramatically developed in recent years with the use of stem cell technology, and these systems may be key tools for overcoming this dilemma and improving our understanding of the dynamic changes in the mitochondrial deficits in patients with psychiatric disorders. We introduce recent discoveries from new experimental models and conclude the discussion by referring to future perspectives. We emphasize the significance of combining studies of human neuronal cell models with those of other experimental systems, including animal models. [ABSTRACT FROM AUTHOR]

New Findings: What is the central question of this study? Heart failure is associated with redistribution of L‐type Ca2+ current (ICa) away from the t‐tubule membrane to the surface membrane of cardiac ventricular myocytes. However, the underlying mechanism and its dependence on severity of pathology (hypertrophy versus failure) are unclear. What is the main finding and its importance? Increasing severity of response to transverse aortic constriction, from hypertrophy to failure, was accompanied by graded loss of t‐tubular ICa and loss of regulation of ICa by caveolin 3. Thus, the pathological loss of t‐tubular ICa, which contributes to impaired excitation–contraction coupling and thereby cardiac function in vivo, appears to be attributable to loss of caveolin 3‐dependent stimulation of t‐tubular ICa. Abstract: Previous work has shown redistribution of L‐type Ca2+ current (ICa) from the t‐tubules to the surface membrane of rat ventricular myocytes after myocardial infarction. However, whether this occurs in all species and in response to other insults, the relationship of this redistribution to the severity of the pathology, and the underlying mechanism, are unknown. We have therefore investigated the response of mouse hearts and myocytes to pressure overload induced by transverse aortic constriction (TAC). Male C57BL/6 mice underwent TAC or equivalent sham operation 8 weeks before use. ICa and Ca2+ transients were measured in isolated myocytes, and expression of caveolin 3 (Cav3), junctophilin 2 (Jph2) and bridging integrator 1 (Bin1) was determined. C3SD peptide was used to disrupt Cav3 binding to its protein partners. Some animals showed cardiac hypertrophy in response to TAC with little evidence of heart failure, whereas others showed greater hypertrophy and pulmonary congestion. These graded changes were accompanied by graded cellular hypertrophy, t‐tubule disruption, decreased expression of Jph2 and Cav3, and decreased t‐tubular ICa density, with no change at the cell surface, and graded impairment of Ca2+ release at t‐tubules. C3SD decreased ICa density in control but not in TAC myocytes. These data suggest that the graded changes in cardiac function and size that occur in response to TAC are paralleled by graded changes in cell structure and function, which will contribute to the impaired function observed in vivo. They also suggest that loss of t‐tubular ICa is attributable to loss of Cav3‐dependent stimulation of ICa. [ABSTRACT FROM AUTHOR]

New Findings: What is the central question of this study? Although electrophysiological and biophysical characteristics of heart fibroblasts have been studied in detail, their responses to prominent paracrine agents in the myocardium have not been addressed adequately. Our experiments characterize changes in cellular electrophysiology and intracellular calcium in response to ATP. What is the main finding and its importance? In rat ventricular fibroblasts maintained in cell culture, we find that ATP activates a specific subset of Ca2+‐activated Cl− channels as a consequence of binding to P2Y purinoceptors and then activating phospholipase C. This response is not dependent on [Ca2+]o but requires an increase in [Ca2+]i and is modulated by the type of nucleotide that is the purinergic agonist. Abstract: Effects of ATP on enzymatically isolated rat ventricular fibroblasts maintained in short‐term (36–72 h) cell culture were examined. Immunocytochemical staining of these cells revealed that a fibroblast, as opposed to a myofibroblast, phenotype was predominant. ATP, ADP or uridine 5′‐triphosphate (UTP) all produced large increases in [Ca2+]i. Voltage‐clamp studies (amphotericin‐perforated patch) showed that ATP (1–100 μ m) activated an outwardly rectifying current, with a reversal potential very close to the Nernst potential for Cl−. In contrast, ADP was much less effective, and UTP produced no detectable current. The non‐selective Cl− channel blockers niflumic acid, DIDS and NPPB (each at 100 μ m), blocked the responses to 100 μ m ATP. An agonist for P2Y purinoceptors, 2‐MTATP, activated a very similar outwardly rectifying C1− current. The P2Y receptor antagonists, suramin and PPADS (100 μ m each), significantly inhibited the Cl− current produced by 100 μ m ATP. ATP was able to activate this Cl− current when [Ca2+]o was removed, but not when [Ca2+]i was buffered with BAPTA‐AM. In the presence of the phospholipase C inhibitor U73122, this Cl− current could not be activated. PCR analysis revealed strong signals for a number of P2Y purinoceptors and for the Ca2+‐activated Cl− channel, TMEM16F (also denoted ANO6). In summary, these results demonstrate that activation of P2Y receptors by ATP causes a phospholipase C‐dependent increase in [Ca2+]i, followed by activation of a Ca2+‐dependent Cl− current in rat ventricular fibroblasts. [ABSTRACT FROM AUTHOR]

Calcium and phosphate are vital for the organism and constitute essential components of the skeleton. Serum levels are tightly hormonally regulated and maintained by exchange with three major sources: the intestines, the kidney and the bone. The effects of sex steroids on the bone have been extensively studied and it is well known that sex steroid deficiency induces bone loss, indirectly influencing renal calcium and phosphate homeostasis. However, it is unknown whether sex steroids also directly regulate renal calcium and phosphate handling, hereby potentially indirectly impacting on bone. The presence of androgen receptors (AR) and estrogen receptors (ER) in both human and rodent kidney, although their exact localization within the kidney remains debated, supports direct effects. Estrogens stimulate renal calcium reabsorption as well as phosphate excretion, while the effects of androgens are less clear. Many of the studies performed with regard to renal calcium and/or phosphate homeostasis do not correct for the calcium and phosphate fluxes from the bone and intestines, which complicates the differentiation between the direct effects of sex steroids on renal calcium and phosphate handling and the indirect effects via the bone and intestines. The objective of this study is to review the literature and current insight of the role of sex steroids in calcium and phosphate handling in the kidney. [ABSTRACT FROM AUTHOR]

To ensure optimal calcium accrual in the fetal skeleton, a substantial rise occurs in 1,25-dihydroxyvitamin D (1,25(OH)2D), but is dependent on sufficient 25-hydroxyvitamin (25(OH)D). Large longitudinal studies addressing free 25(OH)D and 1,25(OH)2D during pregnancy are scarce. We aimed to assess levels of and relationship between 25(OH)D, 1,25(OH)2D, vitamin D-binding protein (DBP), parathyroid hormone (PTH), and free 25(OH)D during pregnancy; determinants of vitamin D status; and association between vitamin D indices or PTH and pregnancy outcomes (gestational diabetes mellitus and birthweight). Altogether 855 pregnant Norwegian Caucasian women from Trondheim and Stavanger (latitude 63°N and 58°N) were recruited; 94 were lost to follow-up. The study was originally a randomized controlled trial (2007–2009) with gestational diabetes as primary outcome. Data were collected in second and third trimester. In third trimester, 246 (34%) had vitamin D insufficiency and 52 (7%) deficiency (25(OH)D <50 and <30nmol/L, respectively). During wintertime in third trimester, 61 (47%) from Trondheim and 23 (51%) from Stavanger exhibited vitamin D insufficiency. PTH was elevated in 27 (3.7%). Estimate of change between trimesters was (95% CI): 25(OH)D -1.8 (-2.8 to -0.7) nmol/L, DBP 0.62 (0.57 to 0.66) μmol/L, calculated free 25(OH)D -1.7 (-2.0 to -1.4) pmol/L, PTH 0.81 (0.72 to 0.90) pmol/L, 1,25(OH)2D (sub-analysis) 31.4 (CI 24.7 to 38.2) pmol/L. A decrease in 1,25(OH)2D occurred in 45% of those with vitamin D deficiency, and they also exhibited lower levels than women with adequate vitamin D status. No association of vitamin D indices and PTH with pregnancy outcomes was observed. Women in Trondheim displayed lower 25(OH)D levels, despite minor latitudinal differences. Less than one-fifth adhered to the authorities’ vitamin D recommendations. These findings demonstrate that hypovitaminosis D is prevalent among pregnant women living in northern latitudes, especially during the dark season, and there is an unmet need to ensure adequate vitamin D intake. [ABSTRACT FROM AUTHOR]

Calcium (Ca 2+ ) is considered one of the most-important biological cations, because it is implicated in cell physiopathology and cell fate through a finely tuned signaling system. In support of this notion, Ca 2+ is the primary driver of cell proliferation and cell growth; however, it is also intimately linked to cell death. Functional abnormalities or mutations in proteins that mediate Ca 2+ homeostasis usually lead to a plethora of diseases and pathogenic states, including cancer, heart failure, diabetes, and neurodegenerative disease. In this review, we examine recent discoveries in the highly localized nature of Ca 2+ -dependent signal transduction and its roles in cell fate, inflammasome activation, and synaptic transmission. [ABSTRACT FROM AUTHOR]

Karst topography is formed from the dissolution of soluble rocks, such as limestone and dolomite. In soils of such a landform, excessive contents of exchangeable calcium seriously limit the growth of vegetations. Researches have proved that rhizosphere microorganisms and endophytes help host plants to adapt to various adverse environments. The adaptive capacity of plants that grow in adverse environment with salt, drought, thermal and heavy metal stresses partially or completely comes from symbiotic microorganisms. By using the high-throughput amplicon sequencing, the bacterial community structures in soil with high calcium contents and roots and leaves of Cochlearia henryi that is commonly seen in karst area were analyzed. The bacteria community structures in these three compartments showed obvious differences. This indicates that C. henryi, which is adaptive to high calcium stress, selectively co-exists with specific bacteria. Although the bacteria community structures in these three compartments differed significantly, there were 73 operational taxonomic units (OTUs) shared by karst soils as well as roots and leaves of C. henryi. The phylogenetic diversity of these 73 OTUs differed significantly from that of overall OTUs detected. There were also obvious differences in KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways and abundance values between the 73 OTUs and overall bacterial communities. A large number of OTUs shared by the karst soils, roots and leaves of C. henryi had close genetic relationship with known stress-resistant bacterial strains. Our results showed that the functional bacteria can be predicted by exploring core bacteria, bacteria shared by soils, adaptable plant roots and leaves. This information will potentially accelerate studies on natural microbial communities which can promote the adaptive capacity of host plants to high calcium stress, and will be valuable for finding microbial strains for field application in karst topography. [ABSTRACT FROM AUTHOR]

Cardiac fibrosis is one of the primary mechanisms of ventricular remodeling, and there is no effective method for reversal. Activation of calcium sensing receptor (CaSR) has been reported to be involved in the development of myocardial fibrosis, but the molecular mechanism for CaSR activation has not yet been clarified and needs to be further explored. Here, we found that AngII induces cardiac fibroblast proliferation and phenotypic transformation in a dose-dependent manner with increased CaSR and autophagy related protein (Beclin1, LC3B) expression. CaSR activation results in intracellular calcium release, MEK1/2 pathway phosphorylation, autophagy activation and collagen formation induced by AngII in cardiac fibroblasts. However, pretreating the cells with Calhex 231 , PD98059 or 3-MA partially blocked AngII-induced cardiac fibrosis. Our data indicate that the activation of CaSR-mediated MEK/ERK and autophagic pathways is involved in AngII-induced cardiac fibrosis in vitro. [ABSTRACT FROM AUTHOR]

Abstract: Premenstrual syndrome (PMS) consists of repetitious physical and psychological symptoms. The symptoms occur during the luteal phase of the menstrual period and cease when the menstrual period starts. This study included pre‐test and post‐test experiments between a control group and a test group. The statistical population involved 40 females, chosen based on multistage cluster sampling. The participants were then divided into four groups to undergo treatment with calcium supplement plus vitamin D together with cognitive behavioral therapy (CBT), and were screened with the Premenstrual Syndrome Screening Test (PSST). The pre‐test and post‐test scores in the PSST, the General Health Questionnaire (GHQ‐28), and Bell's Adjustment Inventory (BAI) were used as assessment tools (p < .05). According to the parameters of PMS symptoms, when evaluating the pre‐test and post‐test scores, the overall score of each individual in the experimental group was improved and a significant effect for the combination of calcium supplement plus vitamin D together with CBT was observed in comparison to the post‐test control group. A comparison of multivariate analysis of covariance (MANCOVA) results collected from the pre‐test and post‐test scores revealed that the method of treatment was beneficial for PMS, adjustment, and general health. [ABSTRACT FROM AUTHOR]

We have used cell culture of astrocytes aligned within microchannels to investigate calcium effects on primary cilia morphology. In the absence of calcium and in the presence of flow of media (10 μL.s-1) the majority (90%) of primary cilia showed reversible bending with an average curvature of 2.1 ± 0.9 × 10-4 nm-1. When 1.0 mM calcium was present, 90% of cilia underwent bending. Forty percent of these cilia demonstrated strong irreversible bending, resulting in a final average curvature of 3.9 ±1 × 10-4 nm-1, while 50% of cilia underwent bending similar to that observed during calcium-free flow. The average length of cilia was shifted toward shorter values (3.67 ±0.34 μm) when exposed to excess calcium (1.0 mM), compared to media devoid of calcium (3.96 ± 0.26 μm). The number of primary cilia that became curved after calcium application was reduced when the cell culture was pre-incubated with 15 μM of the microtubule stabilizer, taxol, for 60 min prior to calcium application. Calcium caused single microtubules to curve at a concentration ≈1.0 mM in vitro, but at higher concentration (≈1.5 mM) multiple microtubule curving occurred. Additionally, calcium causes microtubule-associated protein-2 conformational changes and its dislocation from the microtubule wall at the location of microtubule curvature. A very small amount of calcium, that is 1.45 × 1011 times lower than the maximal capacity of TRPPs calcium channels, may cause gross morphological changes (curving) of primary cilia, while global cytosol calcium levels are expected to remain unchanged. These findings reflect the non-linear manner in which primary cilia may respond to calcium signaling, which in turn may influence the course of development of ciliopathies and cancer. [ABSTRACT FROM AUTHOR]

Background: neonatal hyperbilirubinemia is a common condition in the first few days of life(1) and it can be divided into: pathological and physiological and indirect (unconjugated) and direct (conjugated) hyperbilirubinemia. Objective: This paper aimed to evaluate the effect of different types of phototherapy on serum calcium of both preterm and full-term infants with indirect hyperbilirubinemia, in either supine or prone position. Methods: data were taken from 100 newborns candidate by divided them into two groups. Blue and white light phototherapy were equally used for different infants of both groups. Results: the results showed that 31% developed hypocalcemia, 20% preterm and 11% full term infants. 38% developed hypocalcemia, where among infants who received prophylactic phototherapy 24% developed hypocalcemia. 60% of infants who received extensive phototherapy developed hypocalcemia, where 27.7% of infants who managed with single phototherapy developed hypocalcemia. Seventeen of the infants who managed in prone position and 14 infants of those who received phototherapy in supine position developed hypocalcemia. Conclusion: all in all, 19 infants developed hypocalcemia under blue light and 12 received white light phototherapy. Phototherapy induced hypocalcemia in both full term and premature infants. In addition to the common practice of monitoring the total serum bilirubin and PCV in all newborns on phototherapy, it is important to monitor the total serum calcium on daily base. [ABSTRACT FROM AUTHOR]

1-Methylcyclopropene (1-MCP) can maintain the physical quality of climacteric fruits, such as apple and pear, but inhibit aroma volatile production and fruit flavor. In this study, the effects of calcium (Ca) in combination with 0.6 and 1.0 μL L −1 1-MCP on flesh firmness and aroma volatiles has been investigated on ‘Fuji’ apples stored at room temperature. Results from electronic nose detection and texture evaluation showed that 1-MCP of reduced concentration (0.6 μLL −1 ), but not 1.0 μL L −1 , presented an interactive effect with Ca application on promoting volatile emission and reducing softening. The amount of branched and straight esters and total aroma volatiles, as well as related enzymes including aromatase-related acyltransferase (AAT), alcohol dehydrogenase (ADH), and pyruvate decarboxylase (PDC), were significantly higher in fruit treated with (1-MCP 0.6 + Ca) than 1-MCP 1.0 after 50 and 100 days storage. There was no significant difference between two treatments of (1-MCP 0.6 + Ca) and 1-MCP 1.0 in maintaining fruit firmness. Fruit treated with (1-MCP 0.6 + Ca) had higher aroma quality than 1-MCP 1.0 according to sensory evaluation, but showed no significant difference in terms of texture quality. In conclusion, 1-MCP of reduced concentration combined with Ca treatment had synergetic effect on the aroma formation and softening inhibition of apple fruit, resulting in advanced sensory quality. [ABSTRACT FROM AUTHOR]