Amount Of Intracellular Calcium Research Articles

P0866EVALUATION OF ERYPTOSIS IN PATIENTS WITH CHRONIC KIDNEY DISEASE

Abstract Background and Aims One of the many factors in the pathogenesis of renal anaemia, is eryptosis. The aim of this study is to evaluate eryptosis in patients with chronic renal disease stage 3-5 and 5 dialysis (5D). Method Patients with CKD who were monitored in our nephrology department were included in the study. The age range of the patient groups was 18-80 years and haemoglobin levels were <13 g / dl in men and <12 g / dl in women. As parameters of eryptosis, flow cytometric annexin V binding and intracellular calcium, and superoxide dismutase (SOD) activity with ELISA method were measured in 59 predialysis patient (eGFR<60 mL / min 1.73 m2), 26 haemodialysis patient, 21 peritoneal dialysis patient and 29 healthy volunteers with similar age (control). Haematological and biochemical tests including complete blood count(CBC), erythrocyte sedimentation rate (ESR), Parathormone (PTH), 25-OH vit D3, Blood urea nitrogen (BUN), Creatinine (Cr), C-reactive protein (CRP), Na, K, phosphor (P), ionized and total Calcium, Ferritin, B12 and Folate, were performed. IBM SPSS Statistics Version 20.0 was used for statistical analysis of the data Results The amount of intracellular calcium were 3.05 ± 1.66 in predialysis group, 2.24 ± 0.99 in haemodialysis group, 2.38 ± 0.87 in peritoneal dialysis group and 1.71 ± 0.46 in control group. For intracellular calcium there was statistically significant difference only between predialysis group and control group (p <0. 000). Annexin V binding were calculated as 1.05 ± 0.99 in predialysis group, 1.15 ± 0.56 in haemodialysis group, 1.06 ± 0.87 in peritoneal dialysis group and 0.88 ± 0.86 in control group. Comparing to control group annexin V binding in predialysis, haemodialysis and peritoneal dialysis groups, were statistically significantly increased (for all p <0.000). SOD activity was 0.07 ± 0.07 in predialysis group, 0.13 ± 0.08 in haemodialysis group, 0.14 ± 0.07 in peritoneal dialysis group and 0.03 ± 0.01 in control group. The difference between the control group and dialysis group was statistically significant (p <0. 00). Comparing to nonusers; patients using calcium channel blockers (CCB) had low annexin V binding level (p = 0.013). Patients using erythropoietin (EPO) had elevated annexin V binding level (p <0.000) and lower intracellular calcium (p = 0.014) according to non- users. Conclusion We determined increased eryptosis in patients with CKD stage 3-5 and 5D in our study. Inflammation and elevated parathormone were also associated with increased eryptosis. Therefore, eryptosis may be an important factor in the pathogenesis of renal anaemia. Inflammation associated CKD may increase eryptosis. In addition, this effect can be taken into consideration in the planning of treatment because of the lower incidence of eryptosis in patients using calcium channel blocker and EPO.

In vitro Osteogenic impulse effect of Dexamethasone on periodontal ligament stem cells.

Periodontium is a complex organ composed of mineralized epithelial and connective tissue. Dexamethasone could stimulate proliferation of osteoblast and fibroblasts. This study aimed to assess the osteogenic effect of dexamethasone on periodental ligament (PDL) stem cells. PDL stem cells were collected from periodontal ligament tissue of root of extracted premolar of young and healthy people. The stem cells were cultured in α-MEM Medium in three groups, one group with basic medium contains (α- MEM and FBS 10 % and 50 mmol of β_ gelisrophosphat and L_ ascorbic acid µg/ml), the second group: basic medium with dexamethasone and the third one: basic medium without any osteogenic stimulant. Mineralization of cellular layer was analyzed with Alizarin red stain method. Osteogenic analysis was done by Alkaline phosphates and calcium test. These analysis indicated that the amount of intra-cellular calcium and alkaline phosphates in the Dexamethasone group was far more than the control and basic group (P<0.05). The results of Alizarin red stain indicated more mineralization of cultured cells in Dexamethasone group (P<0.05). The study results showed that Dexamethasone has significant osteogenic effect on PDL stem cells and further studies are recommended to evaluate its effect on treatment of bone disorders.

The proteins (12 and 15 kDa) isolated from heat-killed Lactobacillus plantarum L67 induces apoptosis in HT-29 cells.

A number of scientific studies have revealed that Lactobacillus strains have beneficial bioactivities in the gastrointestinal tract. In this study, the production of intracellular reactive oxygen species (ROS) and the amounts of intracellular calcium, protein kinase C activity, cytochrome c, Bid, Bcl-2, Bax and the apoptosis-mediated proteins [caspase-8, caspase-3 and poly ADP ribose polymerase (PARP)] were evaluated to understand the induction of programmed cell death in HT-29 cells by Lactobacillus plantarum L67. The results obtained from this study indicated that the relative intensities of the apoptotic-related factors (intracellular ROS and intracellular calcium) and of apoptotic signals (Bax and t-Bid) increased with increasing concentrations of the membrane proteins isolated from heat-killed L. plantarum L67, whereas the relative intensities of cytochrome c, Bcl-2, caspase-8, caspase-3 and PARP decreased. This study determines whether proteins (12 and 15 kDa) isolated from heat-killed L. plantarum L67 induce programmed cell death in HT-29 cells. Proteins isolated from L. plantarum L67 can stimulate the apoptotic signals and then consequently induce programmed cell death in HT-29 cells. The results in this study suggest that the proteins isolated from L. plantarum L67 could be used as an antitumoural agent in probiotics and as a component of supplements or health foods.

T Cells Cause Trouble

Immunology Multiple sclerosis (MS) results from inappropriate immune responses against antigens in the central nervous system (CNS). CD4+ T cells that make interleukin-17 (TH17 cells) are a major contributor to the development and pathogenesis of MS. Two recent studies now reveal how TH17 cells are regulated in the CNS and they how might contribute to disease. Using a mouse model of MS, Hao et al. show that natural killer (NK) cells residing in the CNS play a critical role in suppressing TH17 cell responses. NK cells do not act directly on the TH17 cells, however. Instead, they kill microglia, which present antigens and provide cytokine cues to direct TH17 cell differentiation in the CNS. Siffrin et al. focus on how TH17 cells contribute to disease pathogenesis, also in a mouse model of MS. They show, through use of cell transfer experiments and intravital imaging, that TH17 cells (but not other CD4+ helper cell sub-sets) form long-lived contacts with neurons in the CNS of diseased mice. Neurons interacting with TH17 cells exhibited elevated amounts of intracellular calcium, which is indicative of neuronal toxicity, and in vitro, TH17 cells induced neuronal cell death. Together, these studies underscore the importance of TH17 cells in MS pathology and suggest that these cells, and NK cells, may be potential targets for therapeutic intervention. J. Exp. Med. 209 , 1907 (2010); Immunity 33 , 424 (2010).

Effects of Low Power Laser Irradiation on Intracellular Calcium and Histamine Release in RBL‐2H3 Mast Cells

Although laser irradiation has been reported to promote skin wound healing, the mechanism is still unclear. As mast cells are found to accumulate at the site of skin wounds we hypothesized that mast cells might be involved in the biological effects of laser irradiation. In this work the mast cells, RBL-2H3, were used in vitro to investigate the effects of laser irradiation on cellular responses. After laser irradiation, the amount of intracellular calcium ([Ca2+]i) was increased, followed by histamine release, as measured by confocal fluorescence microscopy with Fluo-3/AM staining and a fluorescence spectrometer with o-phthalaldehyde staining, respectively. The histamine release was mediated by the increment of [Ca2+]i from the influx of the extracellular buffer solution through the cation channel protein, transient receptor potential vanilloid 4 (TRPV4). The TRPV4 inhibitor, Ruthenium Red (RR) can effectively block such histamine release, indicating that TRPV4 was the key factor responding to laser irradiation. These induced responses of mast cells may provide an explanation for the biological effects of laser irradiation on promoting wound healing, as histamine is known to have multi-functions on accelerating wound healing.

Agonists increase the sensitivity of contractile elements for Ca ++ in pregnant rat myometrium

OBJECTIVE: The effects of agonists and guanosine 5’-triphosphate binding proteins (G proteins) on contractile properties were investigated in rat longitudinal myometrial tissues in late gestation and during delivery. STUDY DESIGN: The effect of carbachol was examined on the intracellular Ca ++ concentration in intact thin muscle strips from pregnant rat myometrium. In addition, the action of carbachol with guanosine 5'-triphosphate was examined on the Ca ++-induced contractions in β-escin - treated skinned strips (membrane-permeable conditions and chemical clamping of intracellular Ca ++ concentrations). The effects of guanosine 5'-0-( γ-thiotriphosphate) (a nonhydrolyzable analog of guanosine 5'-triphosphate), prostaglandin F 2α with guanosine 5'-triphosphate, prostaglandin E 2 with guanosine 5'-triphosphate, and okadaic acid (a phosphatase inhibitor) were also examined in skinned strips. RESULTS: In intact longitudinal rat myometrium at late gestation the maximum contractions induced by carbachol were larger than the maximum contractions induced by high K + (118 mmol/L), whereas increases in intracellular Ca ++ concentration produced by both agents were similar. In β-escin - treated skinned myometrial strips from late gestation, 0.3 μmol/L Ca ++ evoked contractions. Carbachol (10 μmol/L) plus guanosine 5'-triphosphate (10 μmol/L) enhanced the 0.3 μmol/L Ca ++-induced contractions of skinned strips; the increase was antagonized by 1 mmol/L guanosine 5'-0-( β-thiodiphosphate). Guanosine 5'-0-( γ-thiotriphospate) (0.1 to 100 μmol/L), prostaglandin F 2α (10 μmol/L) plus guanosine 5'-triphosphate (10 μmol/L), prostaglandin E 2 (10 μmol/L) plus guanosine 5'-triphosphate (10 μmol/L), and okadaic acid (1 nmol/L) also augmented 0.3 μmol/L Ca ++ contractions in skinned strips. The increases of 0.3 μmol/L Ca ++-induced contractility by the agonists with guanosine 5'-triphosphate or guanosine 5'-0-( γ-thiotriphosphate) were similar between late gestation and delivery. CONCLUSION: These results suggest that agonists such as carbachol, prostaglandin F 2α , and prostaglandin E 2 enhance the Ca ++-induced contraction of myometrium at late gestation through G protein - mediated mechanisms. The agonist/G protein - mediated Ca ++-sensitizing effects on contractile elements produce additional contractile force with the same amount of intracellular calcium, thus providing expelling forces for delivery of the fetuses. (Am J Obstet Gynecol 1996;175:199-206.)

Differentiation between the short and long term effects of glucose on the intracellular calcium content of the pancreatic beta-cell.

The problem of how glucose affects the intracellular (La3+-nondisplaceable) calcium content of pancreatic beta-cells was approached by combining measurements of 45Ca in ob/ob-mouse islets loaded to isotopic equilibrium with determinations of calcium using electrothermal atomic absorption spectroscopy. Whereas short term changes of the glucose concentration induced marked alterations of insulin release, the islet content of intracellular 45Ca was remarkably stable. The chronic actions of glucose differed from the acute ones in being readily demonstrable and sometimes resulting even in a suppression of the calcium content. Thus, after 7 days of culture in 20 mM glucose, the amount of intracellular calcium was actually lower than when the islets were cultured at 5.5 mM glucose. The long term effect of glucose in suppressing the islet content of intracellular calcium was associated with degranulation and loss of immunoreactive insulin, indicated both from staining of the beta-cells and measurements of the extracted hormone by RIA. The previously unknown ability of glucose to suppress the islet content of intracellular calcium may consequently result from mobilization of the secretory granules.

The role of calcium in cellular dysfunction

In order to study the effects of substances with selective Ca 2+ entry blocking properties which enhance the tolerance to ischemia by preventing a toxic calcium overload, attempts are made to localize calcium ultrastructurally. Under normoxic conditions, a mobile pool of Ca 2+ is localized in synaptic vesicles and in mitochondria of brain cells; in mitochondria of cardiac, skeletal and vascular smooth muscle; and in the junctional SR of fast skeletal muscle. A plasmalemmabound pool of Ca 2+ is present in cardiac and slow skeletal muscle. Ischemia or hypoxia induce marked shifts in calcium of both the mobile and the plasmalemma-bound pools. Cardiac and skeletal muscle mitochondria scavenge huge amounts of calcium, especially during the reperfusion period following prolonged circulatory arrest. The membrane-bound Ca 2+ is lost under these conditions. In the hypoxic brain, the amount of intracellular calcium clearly parallels the degree of damage. Observations made on peripheral and brain blood vessels show that high amounts of precipitated Ca 2+ cover the myofilaments upon induction of spasm. The antispasmodic effect of the selective Ca 2+-entry blockers flunarizine and lidoflazine is morphologically characterized by the absence of Ca 2+ over the myofilaments in muscle treated as such whereas the extracellular Ca 2+ remained the same. This observation indicates that the entry of Ca 2+ is blocked at the level of the plasma membrane. In the heart and brain these drugs preserve the structural integrity of the plasmalemma-surface coat complex and thereby protect the cells against the devastating consequences of cellular calcium overload.

Mechanical responses of intestinal smooth muscle in a calcium-free medium.

SummaryLongitudinal fibers from the guinea pig ileum undergo a transient increase in muscle tone when they are transferred from a physiological salt solution to a calcium-free solution, The magnitude and duration of the contractile response is enhanced if the muscle is preincubated in a high calcium medium (36 mM). The length of time that the muscle is preincubated in the high calcium medium influences the magnitude of the response as well as the amount of intracellular calcium accumulated by the fibers. The mechanical changes initiated by removing extracellular calcium ions are accompanied by a pronounced increase in the unidirectional efflux of calcium ions. The addition of acetylcholine or a high potassium medium enhances the tone of a muscle that is partially contracted in a calcium-free medium. The addition of 1.8 mM CaCl2 depresses it. However, when the same concentration of CaCl2 is added in the presence of acetylcholine or a high potassium medium it enhances muscle tone even more. We inferred from...