Ca Homeostasis Research Articles

Adaptive Responses of Citrusgrandis Leaves to Copper Toxicity Revealed by RNA-Seq and Physiology.

Copper (Cu)-toxic effects on Citrus grandis growth and Cu uptake, as well as gene expression and physiological parameters in leaves were investigated. Using RNA-Seq, 715 upregulated and 573 downregulated genes were identified in leaves of C. grandis seedlings exposed to Cu-toxicity (LCGSEC). Cu-toxicity altered the expression of 52 genes related to cell wall metabolism, thus impairing cell wall metabolism and lowering leaf growth. Cu-toxicity downregulated the expression of photosynthetic electron transport-related genes, thus reducing CO2 assimilation. Some genes involved in thermal energy dissipation, photorespiration, reactive oxygen species scavenging and cell redox homeostasis and some antioxidants (reduced glutathione, phytochelatins, metallothioneins, l-tryptophan and total phenolics) were upregulated in LCGSEC, but they could not protect LCGSEC from oxidative damage. Several adaptive responses might occur in LCGSEC. LCGSEC displayed both enhanced capacities to maintain homeostasis of Cu via reducing Cu uptake by leaves and preventing release of vacuolar Cu into the cytoplasm, and to improve internal detoxification of Cu by accumulating Cu chelators (lignin, reduced glutathione, phytochelatins, metallothioneins, l-tryptophan and total phenolics). The capacities to maintain both energy homeostasis and Ca homeostasis might be upregulated in LCGSEC. Cu-toxicity increased abscisates (auxins) level, thus stimulating stomatal closure and lowering water loss (enhancing water use efficiency and photosynthesis).

Physiological adaptations in early-lactation cows result in differential responses to calcium perturbation relative to nonlactating, nonpregnant cows

The peripartal cow experiences a rapid change in calcium metabolism at the onset of lactation. Research has focused on understanding how mammary-derived factors, such as serotonin (5HT) and parathyroid hormone like hormone (PTHLH), aid in coordinating these calcemic adaptations to lactation. Therefore, the aim of our study was to determine how induced subclinical hypocalcemia influences physiological responses, specifically the 5HT-PTHLH-Ca axis, in lactating and nonlactating dairy cows to elucidate the potential contribution of the mammary gland. Twelve nonlactating, nonpregnant (NL) multiparous Holstein cows and 12 early-lactation (EL) multiparous Holstein cows received either (1) a continuous 24-h intravenous solution of 0.9% NaCl or (2) 5% ethylene glycol tetraacetic acid (EGTA) solution in 0.9% NaCl (n = 6 EL, n = 6 NL per treatment) with the aim of maintaining blood ionized calcium (iCa) less than 1.0 mM. Mammary gland biopsies were taken immediately after and 48 h after termination of infusion. Blood was sampled hourly during infusion and 4, 8, 12, 24, 48, and 72 h after termination of infusion. Infusion of EGTA successfully decreased blood iCa concentrations. However, EL EGTA-infused cows required increased rates of EGTA infusion to maintain iCa below 1.0 mM. Circulating and mammary serotonin concentrations were increased in EL relative to NL cows, with no difference as a result of EGTA infusion. Mammary PTHLH expression was increased in EL cows, with highest expression observed in EL EGTA-infused cows. Collectively, these data demonstrate the robust adaptations EL cows have to maintain Ca homeostasis and the supporting roles 5HT and PTHLH may play.

Effects of restricted dietary phosphorus supply to dry cows on periparturient calcium status

Restricted dietary P supply to transition dairy cows has recently been reported to beneficially affect the Ca balance of periparturient cows. The objective of the present study was to determine whether this effect on the Ca balance can be reproduced when limiting the P-restricted feeding to the last 4 wk of gestation. A total of 30 dairy cows in late pregnancy were randomly assigned to a dry cow diet with either low or adequate P content (0.16 and 0.30% P in DM, respectively) to be fed in the 4 wk before expected calving. After calving, all cows received the same lactating cow ration with adequate P content (0.46% P in DM). Blood was collected daily from 4 d antepartum until calving, at calving (d 0), 6 and 12 h after calving (d +0.25 and d +0.5, respectively) and on days +1, +2, +3, +4 and +7 relative to calving. Blood gas analyses were conducted to determine the concentration of ionized Ca in whole blood ([Ca2+]), and plasma was assayed for concentrations of inorganic phosphorus ([Pi]), total calcium, parathyroid hormone ([PTH]), 1,25-dihydroxyvitamin D ([1,25-(OH)2D3]), and CrossLaps ([CTX]), a biomarker for bone resorption (Immunodiagnostic Systems GmbH). Repeated-measures ANOVA was conducted to study treatment, time, and lactation number effects. The mean [Ca2+] in P-deprived cows remained above the threshold of 1.10 mmol/L throughout the study, and values were higher compared with cows on adequate P supply between d 0 and d +2 and on d +4. The [Ca2+] differed between treatments at the sampling times d 0, d +0.25, d +0.5, d +2, and d +4. Plasma [PTH] and [1,25-(OH)2D3] did not differ between treatments, but P-deprived cows had greater [CTX] than cows with adequate P supply at d +1, d +2, and d +7. These results indicate that restricted dietary P supply to during the last 4 wk of the dry period improves the Ca homeostasis of these cows in the first days of lactation, an effect that seems to be primarily driven by increased bone tissue mobilization.

TRP-BERT: Discrimination of transient receptor potential (TRP) channels using contextual representations from deep bidirectional transformer based on BERT

Transient receptor potential (TRP) channels are non-selective cation channels that act as ion channels and are primarily found on the plasma membrane of numerous animal cells. These channels are involved in the physiology and pathophysiology of a wide variety of biological processes, including inhibition and progression of cancer, pain initiation, inflammation, regulation of pressure, thermoregulation, secretion of salivary fluid, and homeostasis of Ca2+ and Mg2+. Increasing evidences indicate that mutations in the gene encoding TRP channels play an essential role in a broad array of diseases. Therefore, these channels are becoming popular as potential drug targets for several diseases. The diversified role of these channels demands a prediction model to classify TRP channels from other channel proteins (non-TRP channels). Therefore, we presented an approach based on the Support Vector Machine (SVM) classifier and contextualized word embeddings from Bidirectional Encoder Representations from Transformers (BERT) to represent protein sequences. BERT is a deeply bidirectional language model and a neural network approach to Natural Language Processing (NLP) that achieves outstanding performance on various NLP tasks. We apply BERT to generate contextualized representations for every single amino acid in a protein sequence. Interestingly, these representations are context-sensitive and vary for the same amino acid appearing in different positions in the sequence. Our proposed method showed 80.00% sensitivity, 96.03% specificity, 95.47% accuracy, and a 0.56 Matthews correlation coefficient (MCC) for an independent test set. We suggest that our proposed method could effectively classify TRP channels from non-TRP channels and assist biologists in identifying new potential TRP channels.

Auto-inhibitory intramolecular S5/S6 interaction in the TRPV6 channel regulates breast cancer cell migration and invasion

TRPV6, a Ca-selective channel, is abundantly expressed in the placenta, intestine, kidney and bone marrow. TRPV6 is vital to Ca homeostasis and its defective expression or function is linked to transient neonatal hyperparathyroidism, Lowe syndrome/Dent disease, renal stone, osteoporosis and cancers. The fact that the molecular mechanism underlying the function and regulation of TRPV6 is still not well understood hampers, in particular, the understanding of how TRPV6 contributes to breast cancer development. By electrophysiology and Ca imaging in Xenopus oocytes and cancer cells, molecular biology and numerical simulation, here we reveal an intramolecular S5/S6 helix interaction in TRPV6 that is functionally autoinhibitory and is mediated by the R532:D620 bonding. Predicted pathogenic mutation R532Q within S5 disrupts the S5/S6 interaction leading to gain-of-function of the channel, which promotes breast cancer cell progression through strengthening of the TRPV6/PI3K interaction, activation of a PI3K/Akt/GSK-3β cascade, and up-regulation of epithelial-mesenchymal transition and anti-apoptosis.

Effects of low lead exposure on sperm quality and sperm DNA methylation in adult men

InstructionLead (Pb) exposure is a risk factor for male infertility, but the epigenetic changes in sperm DNAattributable to lead exposure is poorly defined.MethodsIn this study, we investigated whether low Pb exposure (< 10 µg/dL) affects the sperm quality. Blood, urine, and semen samples of 297 men of childbearing age were analyzed for all relevant parameters. Based on the blood Pb level (BLL), participants were allocated to RL (0–2.5 µg/dL), RM (2.5–5 µg/dL), and RH (5–10 µg/dL) groups. The 5-methylcytosine and 5-hydroxymethylcytosine patterns in the sperm DNA were identified using methylated DNA immunoprecipitation and hydroxymethylated DNA immunoprecipitation sequencing.ResultsThe non-progressive motility (NP) was significantly increased and associated with global hypomethylation of sperm DNA in the RH group compared with the RL group, indicating that aberrant sperm methylation due to low Pb exposure is possibly associated with reduced sperm motility. The hypomethylated promoter regions were primarily enriched in the calcium (Ca) homeostasis pathway. Further, the interaction between Ca and Pb was associated with sperm rapid progressive motility and asthenospermia risk, although no significant methylation abnormality was observed in those with BLL < 5 µg/dL. When BLL was > 5 µg/dL or when predicting NP, no significant Pb–Ca interaction was observed.DiscussionOverall, our results indicate that aberrant DNA methylation of the Ca homeostasis pathway, induced by low Pb exposure, is the potential cause for reduced sperm velocity.

Mixtures of rare earth elements show antagonistic interactions in Chlamydomonas reinhardtii

In order to better understand the environmental risks of the rare earth elements (REEs), it is necessary to determine their fate and biological effects under environmentally relevant conditions (e.g. at low concentrations, REE mixtures). Here, the unicellular freshwater microalga, Chlamydomonas reinhardtii, was exposed for 2h to one of three soluble REEs (Ce, Tm, Y) salts at 0.5μM or to an equimolar mixture of these REEs. RNA sequencing revealed common biological effects among the REEs. Known functions of the differentially expressed genes support effects of REEs on protein processing in the endoplasmic reticulum, phosphate transport and the homeostasis of Fe and Ca. The only stress response detected was related to protein misfolding in the endoplasmic reticulum. When the REEs were applied as a mixture, antagonistic effects were overwhelmingly observed with transcriptomic results suggesting that the REEs were initially competing with each other for bio-uptake. Metal biouptake results were consistent with this interpretation. These results suggest that the approach of government agencies to regulate the REEs using biological effects data from single metal exposures may be a largely conservative approach.

Effects of vitamin D3 supplementation in gilthead seabream (Sparus aurata) juveniles fed diets high in plant based feedstuffs

Modern aquaculture feeds tend to contain lower levels of fish based ingredients, while increasing the content of plant ingredients. However, this may alter the vitamin profile of the feeds, leading to unbalanced vitamin supply. Requirements for several vitamins have been established for species such as carps and salmonids, but adequate levels for gilthead sea bream are yet unknown.Vitamin D is mainly involved in Ca homeostasis by regulating Ca uptake and liberation from bone intervening in bone remodeling. Fish are unable to synthesize vitamin D and so require absorbing it directly from the diet, thus, it is considered essential for fish. A practical plant-based diet containing 10% fish meal and 6% fish oil containing five levels of vitamin D3 (0.15, 0.43, 0.50, 0.55 and 0.65 mg kg−1 or 5.8, 17.0, 20.0, 22.0 and 26.0 IU g−1) were formulated to identify the optimum levels for gilthead seabream juveniles. Feeding juveniles of gilthead seabream with a range of vitamin D3 levels between 5.8 and 26.0 IU g−1 for 70 days did not markedly alter growth. Increase dietary vitamin D3 significantly raised the liver contents in vitamin D3 in a dose-dependent manner following a potential regression. Increased dietary vitamin D3 levels up to 11.6 IU g−1 may reduce the incidence of skeletal anomalies, particularly caudal and maxillary anomalies, whereas further elevation of dietary vitamin D3 levels increased the concentration of vitamin D3 in liver as well as skeletal anomalies in association to the up-regulation of alp and bmp2 gene expression. The occurrence of myocarditis signs in fish fed vitamin D3 levels of 20.0 IU g−1 or more denote the toxic effects of these dietary levels. These results, together with the increased occurrence of skeletal anomalies in seabream fed the highest dietary vitamin D3 levels, suggest initial signs of hypervitaminosis D. Thus, the recommended level for vitamin D3 for gilthead seabream juveniles fed diets containing high levels of plant ingredients was suggested to be 11.6 IU g−1.

Effects of 25-Hydroxyvitamin D3 and Oral Calcium Bolus on Lactation Performance, Ca Homeostasis, and Health of Multiparous Dairy Cows.

Simple SummarySubclinical hypocalcemia severely affects the lactation and health of dairy cows. Subclinical hypocalcemia is still a concern with cows after postpartum oral Ca; thus, the single treatment approach gradually has shifted to a multitreatment approach in terms of subclinical hypocalcemia. Supplementing 25-hydroxyvitamin D3 could solve the problem of insufficient vitamin D3 synthesis and blocked conversion in transition cows. The present study showed that feeding 25-hydroxyvitamin D3 combined with oral calcium not only improved serum 25-hydroxyvitamin D3 status and calcium homeostasis, but also had potential benefits on lactation performance and the health status during the transition period.Little information is available regarding the effect of supplementing 25-hydroxyvitamin D3 during the transition period combined with a postpartum oral calcium bolus on Ca homeostasis. The objectives of the current study were to evaluate the effects of 25-hydroxyvitamin D3 combined with postpartum oral calcium bolus on lactation performance, serum minerals and vitamin D3 metabolites, blood biochemistry, and antioxidant and immune function in multiparous dairy cows. To evaluate the effects of 25-hydroxyvitamin D3 combined with oral calcium, 48 multiparous Holstein cows were randomly assigned to one of four treatments: (1) supplementing 240 mg/day vitamin D3 without a postpartum oral Ca bolus (control), (2) supplementing 240 mg/day vitamin D3 with an oral Ca bolus containing 90 g of Ca immediately post-calving (Ca + VitD), (3) supplementing 6 g/day 25-hydroxyvitamin D3 without an oral Ca bolus (25D), and (4) supplementing 6 g/day 25-hydroxyvitamin D3 with an oral Ca bolus containing 90 g of Ca immediately post-calving (Ca + 25D). Lactation performance during the first 21 days was measured. Blood was collected at the initiation of calving and then 1, 2, 7, 14, and 21 days relative to the calving date. The yield of milk (0.05 < p < 0.10), energy-corrected milk (p < 0.05), 3.5% fat-corrected milk (p < 0.05), and milk protein (p < 0.05) were significantly higher in 25-hydroxyvitamin D3-treated groups within 3 weeks of lactation than in vitamin D3-treated cows. The iCa (p < 0.05) and tCa (p < 0.05) were higher in both Ca and 25D + Ca cows than in the control and 25D groups within 48 h. The concentrations of serum tCa (p < 0.05), tP (p < 0.05), and 25-hydroxyvitamin D3 (p < 0.05) in 25D and 25D + Ca cows were higher than those in control and Ca cows within 21 days postpartum. Feeding 25-hydroxyvitamin D3 also showed a lower concentration of malondialdehyde (p < 0.05), interleukin 6 (p < 0.05), and tumor necrosis factor-alpha (TNF-α) (p < 0.05), as well as a higher concentration of alkaline phosphatase (p < 0.05), total antioxidant capacity (p < 0.05), and immunoglobulin G (p < 0.05) than vitamin D3. Supplementing Ca bolus also showed lower concentrations of alanine transaminase (p < 0.05) and TNF-α (p < 0.05). In conclusion, supplementing 25-hydroxyvitamin D3 during the transition period combined with a postpartum oral calcium bolus improved lactation performance, Ca homeostasis, and antioxidant and immune function of medium-production dairy cows within 21 days postpartum.

PSIII-6 Gene Expression Profile of Beef Heifer Placental Caruncles Is Affected by Pre-breeding and Early Gestation Micronutrient Supplementation

Abstract Vitamins and minerals are essential for proper fetal and placental development and function. However, the impact of micronutrient supplementation on placental function and gene expression remains unclear. Herein, we performed a transcriptomic analysis to determine the impact of pre-breeding maternal micronutrient supplementation on the gene expression of placental caruncles (CAR; maternal placenta). Crossbred Angus beef heifers were supplemented (VTM, n = 7) or not (CON, n = 7) with 113 g•heifer-1•d-1 of mineral premix (Purina® Wind &amp; Rain® Storm® All-Season 7.5 Complete) from d 71 to 148 before breeding and until d 83 of gestation. After breeding, heifers were fed a diet to gain 0.79 kg/d. Uteroplacental tissues were collected at d 83. The largest placentome closest to the fetus was collected, and CAR was manually dissected from the cotyledon. Total RNA was isolated from CAR, and gene expression was measured with RNA-Seq. After data quality control and read mapping, differential expression was performed using DESeq2. We identified 46 upregulated and 19 downregulated genes in the VTM group (adj.Pval &amp;lt; 0.1). ShinyGO pathway analysis software was used to identify genes in the Ca and CGMP-PKG signaling pathways, including CALM2 and CAMK2G, which were down and upregulated, respectively. Calcium-mediated systems may activate steroidogenic activity in bovine placentomes, while the cGMP-PKG pathway plays a key role in vascular homeostasis mediated by nitric oxide and decreased Ca concentrations. Furthermore, biological processes underlying blood circulation were among those over-represented. Previous studies report that maternal nutrition may impact placental vascularity and uterine blood flow. ATP2B, that is upregulated in the VTM group, is a calcium/calmodulin-regulated, magnesium-dependent protein involved in intracellular Ca homeostasis. In summary, pre-breeding and early gestation maternal micronutrient supplementation leads to differential expression of genes involved in Ca homeostasis and has a putative effect on placenta vascular function.

Impaired Ca2+ Sensitivity of a Novel GCAP1 Variant Causes Cone Dystrophy and Leads to Abnormal Synaptic Transmission Between Photoreceptors and Bipolar Cells.

Guanylate cyclase-activating protein 1 (GCAP1) is involved in the shutdown of the phototransduction cascade by regulating the enzymatic activity of retinal guanylate cyclase via a Ca2+/cGMP negative feedback. While the phototransduction-associated role of GCAP1 in the photoreceptor outer segment is widely established, its implication in synaptic transmission to downstream neurons remains to be clarified. Here, we present clinical and biochemical data on a novel isolate GCAP1 variant leading to a double amino acid substitution (p.N104K and p.G105R) and associated with cone dystrophy (COD) with an unusual phenotype. Severe alterations of the electroretinogram were observed under both scotopic and photopic conditions, with a negative pattern and abnormally attenuated b-wave component. The biochemical and biophysical analysis of the heterologously expressed N104K-G105R variant corroborated by molecular dynamics simulations highlighted a severely compromised Ca2+-sensitivity, accompanied by minor structural and stability alterations. Such differences reflected on the dysregulation of both guanylate cyclase isoforms (RetGC1 and RetGC2), resulting in the constitutive activation of both enzymes at physiological levels of Ca2+. As observed with other GCAP1-associated COD, perturbation of the homeostasis of Ca2+ and cGMP may lead to the toxic accumulation of second messengers, ultimately triggering cell death. However, the abnormal electroretinogram recorded in this patient also suggested that the dysregulation of the GCAP1–cyclase complex further propagates to the synaptic terminal, thereby altering the ON-pathway related to the b-wave generation. In conclusion, the pathological phenotype may rise from a combination of second messengers’ accumulation and dysfunctional synaptic communication with bipolar cells, whose molecular mechanisms remain to be clarified.

Vitamin D level, body mass index and fracture risk in children: vitamin D deficiency and fracture risk.

The objective of this study was to determine the impacts of preventable causes of fracture, such as vitamin D deficiency, disturbed calcium homeostasis and obesity on fracture occurrence in minor traumas. In this way, the effects of relevant parameters on fracture may be further elucidated. A prospective case-control study in children aged 2-18 years children with and without fractures was performed. Participants with a pediatric trauma score higher than 10 presenting to minor trauma were included to exclude the significant impact of severe trauma on fracture. The effects of obesity, parameters associated with vitamin D and Ca homeostasis on fracture occurrence were evaluated. Univariate and multivariate analyses were used to test for associations between fracture status and the assessed variables. The relationships between the variables and the odds of fracture occurrence were examined using logistic regression models. The sample consisted of 76 patients and 50 controls. There were no significant differences between the patients and controls in terms of age, sex, trauma type and pubertal period. The patients had a significantly higher mean BMI percentile (61.2 ± 30.7, 36.7 ± 30.7; P < 0.001). Likewise, patients were more likely than controls to have a lower mean 25(OH)D level and mean phosphorus level (respectively, 13.4 ± 7.0, 17.3 ± 7.8; P = 0.004, and 4.6 ± 0.7, 5.1 ± 0.8; P < 0.001). Moreover, fractures were substantially more frequent in children with vitamin D deficiency (<20 ng/mL, χ2: 7.781, df: 1, P = 0.005). In the multivariate logistic model, BMI percentile and vitamin D levels remained significantly associated with increased odds of fracture [1.02 (1.01-1.04), P < 0.001 and 0.93 (0.89-0.98), P = 0.01]. The present study supports an association of high BMI and vitamin D deficiency with an increased odds of fracture occurrence in children. The findings may help physicians to reduce the risk factors of fracture by preventive efforts. Thus, unexpected health costs and morbidity may be minimized.

The Role of Siglec-G on Immune Cells in Sepsis.

Sepsis is a life-threatening clinical syndrome that results from an overwhelming immune response to infection. During sepsis, immune cells are activated by sensing pathogen-associated molecular patterns and damage-associated molecular patterns (DAMPs) through pattern recognizing receptors (PRRs). Regulation of the immune response is essential to preventing or managing sepsis. Sialic acid-binding immunoglobulin-type lectin-G (Siglec-G), a CD33 group of Siglec expressed in B-1a cells and other hematopoietic cells, plays an important immunoregulatory role. B-1a cells, a subtype of B lymphocytes, spontaneously produce natural IgM which confers protection against infection. B-1a cells also produce IL-10, GM-CSF, and IL-35 to control inflammation. Sialic acids are present on cell membranes, receptors, and glycoproteins. Siglec-G binds to the sialic acid residues on the B cell receptor (BCR) and controls BCR-mediated signal transduction, thereby maintaining homeostasis of Ca++ influx and NFATc1 expression. Siglec-G inhibits NF-κB activation in B-1a cells and regulates B-1a cell proliferation. In myeloid cells, Siglec-G inhibits DAMP-mediated inflammation by forming a ternary complex with DAMP and CD24. Thus, preserving Siglec-G’s function could be a novel therapeutic approach in sepsis. Here, we review the immunoregulatory functions of Siglec-G in B-1a cells and myeloid cells in sepsis. A clear understanding of Siglec-G is important to developing novel therapeutics in treating sepsis.

Transcription factor behaves differently in metallicolous and non-metallicolous populations of

In Arabidopsis thaliana (L.) Heynh., MYB59 transcription factor participates in regulating Ca homeostasis and signal transduction and is induced by Cd excess. To investigate its role in the facultative metallophyte Arabidopsis halleri ssp. halleri (L.) O'Kane and Al-Shehbaz, MYB59 expression was investigated under Cd treatment or Ca depletion in three populations belonging to distinct phylogeographic units (metallicolous PL22 and I16 and non-metallicolous I29), and compared with the expression in A. thaliana. In control conditions, MYB59 transcription in A. thaliana and the non-metallicolous population I29 follow a comparable trend with higher expression in roots than shoots, whereas in metallicolous populations I16 and PL22 its expression is similar in roots and shoots, suggesting a convergent evolution associated with adaptation to metalliferous environments. After 6 h of Ca depletion, MYB59 transcript levels were very high in I16 and PL22 populations, indicating that the adaptation to metalliferous environments requires tightly regulated Ca homeostasis and signalling. Cd treatment caused variability in MYB59 expression. In I29, MYB59 expression, as in A. thaliana, is likely associated to stress response, whereas its modulation in the two metallicolous populations reflects the different strategies for Cd tolerance and accumulation. In conclusion, MYB59 regulation in A. halleri is part of the network linking mineral nutrition and Cd tolerance/accumulation.

The assessment of serum S100B in vitiligo

ObjectiveTo evaluate the role of serum S100B in vitiligo. This may provide a closer understanding of the pathogenesis of this disease entity. Hopefully, this insight can set the route for newer therapeutic approaches.BackgroundVitiligo is an acquired dyschromia of the skin, in which there is a loss of epidermal melanocytes. The prevalence of vitiligo is ~ 0.1–2% worldwide. The exact pathogenesis of vitiligo remains elusive and is likely multifactorial. S100 proteins are localized in the cytoplasm and nucleus of a wide range of cells and involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation.Patients and methodsThis case–control study was carried out on 40 patients with vitiligo and 40 age-matched and sex-matched healthy volunteers as a control group. All participants were subjected to a full history taking, general examination, local examination with determination of site of the lesions, assessment of vitiligo activity and severity, and laboratory investigation for quantitative measurement of S100B protein in vitiligo serum.ResultsThere was a highly significant difference between cases and controls regarding the mean S100B level. There was a significant difference between cases with elevated S100B and normal level of S100B regarding vitiligo area scoring index score. There was a significant positive correlation between S100B and vitiligo disease activity score.ConclusionS100 protein is elevated in patients with vitiligo more than healthy population. This may be owing to that S100 protein is involved in vitiligo pathogenesis through affecting Ca homeostasis and activation of proinflammatory cascade with release of interleukin-1B and interleukin-6.

Modulating ALDH2 reveals a differential dependence on ROS for hypertrophy and SR Ca2+ release in aldosterone-treated cardiac myocytes

Growing evidence links high aldosterone levels with atrial fibrillation and other heart diseases. Here, we have investigated the functional consequences of culturing adult rat atrial myocytes with aldosterone, at the level of cell size, homeostasis of Ca2+, reactive oxygen species (ROS), and nitrogen oxide (NO). The protein levels of NO synthase (NOS), aldehyde dehydrogenase 2 (ALDH2), NADPH oxidase (NOX), and Na+-Ca2+ exchanger (NCX) were also studied. Aldosterone did not alter the expression of these proteins, except for the NCX, which was enhanced by nearly 100%. Additionally, the hormone inhibited and stimulated, respectively, the production of NO and ROS (the effect on ROS appeared after 24 h of treatment and reached a maximum by 4-6 days, with an EC50 of 1.2 nM). These changes in reactive species generation were blunted by tetrahydrobiopterin (BH4, a NOS cofactor), suggesting the involvement of an uncoupled NOS. An activator (Alda-1) and an inhibitor (daidzin) of ALDH2 were used, to determine if this enzyme activity is related to aldosterone effects, through possible modulation of ROS. Aldosterone produced a ∼10% increase in cell size and, remarkably, this hypertrophic effect, along with the corresponding changes in ROS and NO, were all mimicked by daidzin and prevented by Alda-1. Something different happened with SR Ca2+ release. Aldosterone increased both the magnitude of Ca2+ transients and the incidence of spontaneous Ca2+ oscillations, but these actions were not reproduced by daidzin. Moreover, rather than being prevented, they were further promoted by Alda-1, which also increased the rate of SR Ca2+ reuptake. These results suggest that NOS and ALDH2 may prevent some adverse consequences of aldosteronism (in the case of ALDH2, at the expense of exacerbating SR Ca2+ release). Our data also suggest a hierarchical model in which aldosterone promotes: SR Ca2+ release, then ROS production, and finally hypertrophy.

Increased expression of fibroblast growth factor 23 is the signature of a deteriorated Ca/P balance in ageing laying hens

The present study concerned the effect of ageing in laying hens, from 23 to 90 weeks of age, on the regulation of Ca metabolism related to the requirement for eggshell mineralization. Samples were collected from parathyroid gland (PG), liver, jejunum, medullary bone (MB) and kidney for a quantitative study of candidate gene expression. Although parathyroid hormone (PTH) gene expression in the PG did not vary with age, a stronger challenge to Ca homeostasis was suggested in aged hens. Indeed gene expression of Ca transporters , Vitamin D Receptor (VDR) in the jejunum, and that of transient receptor potential channel subfamily V member 5 (TRPV5) in the kidney decreased. This could exacerbate bone resorption and impair bone accretion, as attested by a higher expression of the Carbonic Anhydrase 2 (CA2) gene and a lower expression of collagen type I alpha 1 chain (COL1A1) in the MB. The increased expression of Fibroblast Growth Factor 23 (FGF23) in the MB likely contributed to the decreased plasma levels of 1.25(OH)2D3 and the altered expression of target genes under its regulation. Our data highlights the molecular mechanisms underlying the osteoporotic syndrome previously documented in aged laying hens, thus providing new perspectives for future interventions.

140 Young Scholar Presentation: Immune activation and its effects on energetics and calcium homeostasis

Abstract Nutrient partitioning towards productive processes (i.e., milk production, growth, and reproduction) is key to economically profitable agriculture. During immune activation, the hierarchy of coordinated nutrient trafficking is reprioritized towards the immune system at the expense of production. Dairy cows encounter frequent immune challenges, as bacterial insults can originate from a myriad of sources including the uterus, mammary gland, and gastrointestinal tract. Regardless of the origin, immune activation hinders animal welfare and evidence suggests it may play a role in many post-calving undesirable phenotypes (i.e., decreased DMI, increased NEFA, hypocalcemia). Following activation, leukocytes undergo a metabolic shift from oxidative phosphorylation to aerobic glycolysis (a phenomenon known as the “Warburg effect”) and begin consuming copious amounts of glucose. In a lactating cow the glucose requirement of the acutely activated immune system exceeds 1 kg in a 12-hour period. To ensure adequate glucose delivery to leukocytes several well-characterized metabolic adjustments are employed including hyperglycemia or hypoglycemia (depending on the stage and severity of infection), increased insulin and glucagon, increased skeletal muscle catabolism, hypertriglyceridemia, and hypoketonemia. The energetic burden of immune activation is intensified by a simultaneous decrease in feed intake and thus reduced intestinally derived substrates. In addition to energetic metabolism, immune activation induces a marked and sustained decrease in circulating calcium (Ca). Recently, we have demonstrated that the total Ca deficit was ~20 g during an acute (12 hour) and intense model of immune activation. Infection-induced hypocalcemia is a species conserved response, yet, it remains largely unknown what role Ca plays during infection and why it acutely decreases. Although, evidence suggests it may serve as a protective strategy to prevent a hyper-inflammatory systemic response during infection. In summary, immune activation negatively influences metabolic, hormonal, and Ca homeostasis and these alterations closely mimic changes observed in poorly transitioning dairy cows. Having a better understanding of the impact of immune activation on nutrient trafficking and Ca homeostasis will provide foundational information for developing strategies aimed at minimizing production losses during infection.

TRPV1 Channel: A Noxious Signal Transducer That Affects Mitochondrial Function

The Transient Receptor Vanilloid 1 (TRPV1) or capsaicin receptor is a nonselective cation channel, which is abundantly expressed in nociceptors. This channel is an important transducer of several noxious stimuli, having a pivotal role in pain development. Several TRPV1 studies have focused on understanding its structure and function, as well as on the identification of compounds that regulate its activity. The intracellular roles of these channels have also been explored, highlighting TRPV1′s actions in the homeostasis of Ca2+ in organelles such as the mitochondria. These studies have evidenced how the activation of TRPV1 affects mitochondrial functions and how this organelle can regulate TRPV1-mediated nociception. The close relationship between this channel and mitochondria has been determined in neuronal and non-neuronal cells, demonstrating that TRPV1 activation strongly impacts on cell physiology. This review focuses on describing experimental evidence showing that TRPV1 influences mitochondrial function.

The Association of Parathyroid Hormone Related Protein and Vitamin D Level with Serum Calcium Ion in Acute Leukemia Patients

Acute leukemia is bone marrow clonal cell malignancy. One of its complications is hypercalcemia. Parathyroid Hormone-Related Protein (PTHrP) activities involve the regulation of Calcium (Ca) metabolism. Vitamin D is a steroid involved in Ca homeostasis and bone mineralization. This study aimed to analyze PTHrP and vitamin D levels with serum calcium ion in acute leukemia. A cross-sectional study was performed in Clinical Pathology Dr. Moewardi General Hospital Surakarta between July and August 2019, consisting of 41 subjects with new acute leukemia who were diagnosed based on bone marrow puncture and or immunophenotyping result. The cut-off value of Ca ion serum and PTHrP level were determined with a Receiver Operating Curve (ROC). The data were analyzed with a 2x2 table, followed by multivariate logistic regression analysis, and p&lt;0.05 was considered significant. Statistical analysis showed the median age of 25 (2-68) years, 23 (56.10%) ALL, and 18 (43.90%) non-ALL patients. The median of Ca ion and PTHrP were 1.08 (0.84-1.21) mmol/l and 307.52 (20.77-1104.26) pg/mL, respectively. The mean level of vitamin D was 26.45±11.40 ng/mL. Bivariate analysis showed that PTHrP levels ≥ 110.09 pg/mL and vitamin D ≥ 20 ng/mL were related to serum Ca ion ≥ 1.07 mmol/l (PR 4.675; 95% CI: 1.211-18.041; p=0.021 and PR 5.143; 95% CI: 1.279-20.677; p=0.017). Multivariate analysis showed that PTHrP ≥ 110.09 pg/mL and vitamin D ≥ 20 ng/mL were associated with serum Ca ion ≥1.07 mmol/l. There was a significant association between PTHrP, vitamin D level, and serum Ca ion in acute leukemia patients.