Synthesis, characterization and evaluation of phosphorylated resins in the removal of Pb(2+) from aqueous solutions

Phosphinic-derivative poly(styrene-co-divinylbenzene)-based on PS-DVB copolymers with different porosity degrees have been prepared by aromatic electrophilic substitution reaction using PCl(3)/AlCl(3) followed by base-promoted hydrolysis. The phosphorylation reaction was analyzed by infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetry (TG/DTG). In addition, the phosphorous content of the phosphorylated copolymers was determined by spectrophotometry using the method based on sodium molybdate reactant so that the extension of that modification could be assessed. The performance of the phosphorylated resins in the extraction of Pb(2+) from aqueous solutions in a batch system was also evaluated. The Pb(2+) content was determined by atomic absorption spectrometry (AAS). These materials presented excellent extraction capacity under the contact time of 30 min and pH 6.

Myosin Va phosphorylated on ser(1650) is found in nuclear speckles and redistributes to nucleoli upon inhibition of transcription

Nuclear actin and nuclear myosins have been implicated in the regulation of geneexpression in vertebrate cells. Myosin V is a class of actin-based motor proteins involved in cytoplasmic vesicle transport and anchorage, spindle-pole alignment and mRNA translocation. In this study, myosin-Va, phosphorylated on a conserved serine in the tail domain (phospho-ser(1650) MVa), was localized to subnuclear compartments. A monoclonal antibody, 9E6, raised against a peptide corresponding to phosphoserine(1650) and flanking regions of the murine myosin Va sequence, was immunoreactive to myosin Va heavy chain in cellular and nuclear extracts of HeLa cells, PC12 cells and B16-F10 melanocytes. Immunofluorescence microscopy with this antibody revealed discrete irregular spots within the nucleoplasm that colocalized with SC35, a splicing factor that earmarks nuclear speckles. Phospho-ser(1650) MVa was not detected in other nuclear compartments, such as condensed chromatin, Cajal bodies, gems and perinucleolar caps. Although nucleoli also were not labeled by 9E6 under normal conditions, inhibition of transcription in HeLa cells by actinomycin D caused the redistribution of phospho-ser(1650) MVa to nucleoli, as well as separating a fraction of phosphoser(1650) MVa from SC35 into near-neighboring particles. These observations indicate a novel role for myosin Va in nuclear compartmentalization and offer a new lead towards the understanding of actomyosin-based gene regulation.

Expression of SMAD proteins, TGF-beta/activin signaling mediators, in human thyroid tissues

OBJECTIVE: To investigate the expression of SMAD proteins in human thyroid tissues since the inactivation of TGF-β/activin signaling components is reported in several types of cancer. Phosphorylated SMAD 2 and SMAD3 (pSMAD2/3) associated with the SMAD4 induce the signal transduction generated by TGF-β and activin, while SMAD7 inhibits this intracellular signaling. Although TGF-β and activin exert antiproliferative roles in thyroid follicular cells, thyroid tumors express high levels of these proteins. MATERIALS AND METHODS: The protein expression of SMADs was evaluated in multinodular goiter, follicular adenoma, papillary and follicular carcinomas by immunohistochemistry. RESULTS: The expression of pSMAD2/3, SMAD4 and SMAD7 was observed in both benign and malignant thyroid tumors. Although pSMAD2/3, SMAD4 and SMAD7 exhibited high cytoplasmic staining in carcinomas, the nuclear staining of pSMAD2/3 was not different between benign and malignant lesions. CONCLUSIONS: The finding of SMADs expression in thyroid cells and the presence of pSMAD2/3 and SMAD4 proteins in the nucleus of tumor cells indicates propagation of TGF-β/activin signaling. However, the high expression of the inhibitory SMAD7, mostly in malignant tumors, could contribute to the attenuation of the SMADs antiproliferative signaling in thyroid carcinomas.

Hyperglycemia can delay left ventricular dysfunction but not autonomic damage after myocardial infarction in rodents

Background: Although clinical diabetes mellitus is obviously a high risk factor for myocardial infarction (MI), in experimental studies disagreement exists about the sensitivity to ischemic injury of an infarcted myocardium. Recently, our group demonstrated that diabetic animals presented better cardiac function recovery and cellular resistance to ischemic injury than nondiabetics. In the present study, we evaluated the chronic effects of MI on left ventricular (LV) and autonomic functions in streptozotocin (STZ) diabetic rats. Methods: Male Wistar rats were divided into 4 groups: control (C, n = 15), diabetes (D, n = 16), MI (I, n = 21), and diabetes + MI (DI, n = 30). MI was induced 15 days after diabetes (STZ) induction. Ninety days after MI, LV and autonomic functions were evaluated (8 animals each group). Left ventricular homogenates were analyzed by Western blotting to evaluate the expression of calcium handling proteins. Results: MI area was similar in infarcted groups (similar to 43%). Ejection fraction and + dP/dt were reduced in I compared with DI. End-diastolic pressure was additionally increased in I compared with DI. Compared with DI, I had increased Na(+)-Ca(2+) exchange and phospholamban expression (164%) and decreased phosphorylated phospholamban at serine(16) (65%) and threonine(17) (70%) expression. Nevertheless, diabetic groups had greater autonomic dysfunction, observed by baroreflex sensitivity and pulse interval variability reductions. Consequently, the mortality rate was increased in DI compared with I, D, and C groups. Conclusions: LV dysfunction in diabetic animals was attenuated after 90 days of myocardial infarction and was associated with a better profile of calcium handling proteins. However, this positive adaptation was not able to reduce the mortality rate of DI animals, suggesting that autonomic dysfunction is associated with increased mortality in this group. Therefore, it is possible that the better cardiac function has been transitory, and the autonomic dysfunction, more prominent in diabetic group, may lead, in the future, to the cardiovascular damage.

A role for mammalian target of rapamycin (mTOR) pathway in non alcoholic steatohepatitis related-cirrhosis

Non-alcoholic fatty liver disease (NAFLD) encompasses the whole spectrum of steatosis, nonalcoholic steatohepatitis (NASH), and NASH-related cirrhosis (NASH/Cir). Although molecular advances have been made in this field, the pathogenesis of NAFLD is not completely understood. The gene expression profiling associated to NASH/Cir was assessed, in an attempt to better characterize the pathways involved in its etiopathogenesis. Methods: In the first step, we used cDNA microarray to evaluate the gene expression profiles in normal liver (n=3) and NASH/Cir samples (n=3) by GeneSifter (TM) analysis to identify differentially expressed genes and biological pathways. Second, tissue microarray was used to determine immunohistochemical expression of phosphorylated mTOR and 4E-BP1 in 11 normal liver samples, 10 NASH/Cir samples and in 37 samples of cirrhosis of other etiologies to further explore the involvement of the mTOR pathway evidenced by the gene expression analysis. Results: 138 and 106 genes were, respectively, up and down regulated in NASH/Cir in comparison to normal liver. Among the 9 pathways identified as significantly modulated in NASH/Cir, the participation of the mTOR pathway was confirmed, since expression of cytoplasmic and membrane phospho-mTOR were higher in NASH/Cir in comparison to cirrhosis of other etiologies and to normal liver. Conclusions: Recent findings have suggested a role for the cellular ""nutrient sensor"" mTOR in NAFLD and the present study corroborates the participation of this pathway in NASH/Cir. Phospho-mTOR evaluation might be of clinical utility as a potential marker for identification of NASH/Cir in cases mistakenly considered as cryptogenic cirrhosis owing to paucity of clinical data.

Exercise training and caloric restriction prevent reduction in cardiac Ca(2+)-handling protein profile in obese rats

Previous studies show that exercise training and caloric restriction improve cardiac function in obesity. However, the molecular mechanisms underlying this effect on cardiac function remain unknown. Thus, we studied the effect of exercise training and/or caloric restriction on cardiac function and Ca(2+) handling protein expression in obese rats. To accomplish this goal, male rats fed with a high-fat and sucrose diet for 25 weeks were randomly assigned into 4 groups: high-fat and sucrose diet, high-fat and sucrose diet and exercise training, caloric restriction, and exercise training and caloric restriction. An additional lean group was studied. The study was conducted for 10 weeks. Cardiac function was evaluated by echocardiography and Ca(2+) handling protein expression by Western blotting. Our results showed that visceral fat mass, circulating leptin, epinephrine, and norepinephrine levels were higher in rats on the high-fat and sucrose diet compared with the lean rats. Cardiac nitrate levels, reduced/oxidized glutathione, left ventricular fractional shortening, and protein expression of phosphorylated Ser(2808)-ryanodine receptor and Thr(17-)phospholamban were lower in rats on the high-fat and sucrose diet compared with lean rats. Exercise training and/or caloric restriction prevented increases in visceral fat mass, circulating leptin, epinephrine, and norepinephrine levels and prevented reduction in cardiac nitrate levels and reduced: oxidized glutathione ratio. Exercise training and/or caloric restriction prevented reduction in left ventricular fractional shortening and in phosphorylation of the Ser(2808)-ryanodine receptor and Thr(17)-phospholamban. These findings show that exercise training and/or caloric restriction prevent cardiac dysfunction in high-fat and sucrose diet rats, which seems to be attributed to decreased circulating neurohormone levels. In addition, this nonpharmacological paradigm prevents a reduction in the Ser(2808)-ryanodine receptor and Thr(17-)phospholamban phosphorylation and redox status. (Hypertension. 2010;56:629-635.)

Cyclic Guanosine Monophosphate Signaling Cascade Mediates Pigment Aggregation in Freshwater Shrimp Chromatophores

The cell signaling cascades that mediate pigment movements in crustacean chromatophores are not yet well established, although Ca(2+) and cyclic nucleotide second messengers are involved. Here, we examine the participation of cyclic guanosine monophosphate (cGMP) in pigment aggregation triggered by red pigment concentrating hormone (RPCH) in the red ovarian chromatophores of freshwater shrimp. In Ca(2+)-containing (5.5 mmol l(-1)) saline, 10 mu mol l(-1) dibutyryl cGMP alone produced complete pigment aggregation with the same time course (approximate to 20 min) and peak velocity (approximate to 17 mu m/min) as 10(-8) mol l(-1) RPCH; however, in Ca(2+)-free saline (9 X 10(-11) mol l(-1) Ca(2+)), db-cGMP was without effect. The soluble guanylyl cyclase (GC-S) activators sodium nitroprusside (SNP, 0.5 mu mol l(-1)) and 3-morpholinosydnonimine (SIN-1, 100 mu mol l(-1)) induced moderate aggregation by themselves (approximate to 35%-40%) but did not affect RPCH-triggered aggregation. The GC-S inhibitors zinc protoporphyrin IX (ZnPP-XI, 30 mu mol l(-1)) and 6-anilino-5,8-quinolinedione (LY83583, 10 mu mol l(-1)) partially inhibited RPCH-triggered aggregation by approximate to 35%. Escherichia coli heat-stable enterotoxin (STa, 1 mu mol l(-1)), a membrane-receptor guanylyl cyclase stimulator, did not induce or affect RPCH-triggered aggregation. We propose that the binding of RPCH to an unknown membrane-receptor type activates a Ca(2+)-dependent signaling cascade coupled via cytosolic guanylyl cyclase and cGMP to protein kinase G-phosphorylated proteins that regulate aggregation-associated, cytoskeletal molecular motor activity. This is a further example of a cGMP signaling cascade mediating the effect of a crustacean X-organ neurosecretory peptide.

High Penetrance of Pheochromocytoma Associated with the Novel C634Y/Y791F Double Germline Mutation in the RET Protooncogene

Context: Previous studies have shown that double RET mutations may be associated with unusual multiple endocrine neoplasia type 2 (MEN 2) phenotypes. Objective: Our objective was to report the clinical features of patients harboring a previously unreported double mutation of the RET gene and to characterize this mutation in vitro. Patients: Sixteen patients from four unrelated families and harboring the C634Y/Y791F double RET germline mutation were included in the study. Results: Large pheochromocytomas measuring 6.0-14 cm and weighing upto 640 g were identified in the four index cases. Three of the four tumors were bilateral. High penetrance of pheochromocytoma was also seen in the C634Y/Y791F-mutation-positive relatives (seven of nine, 77.7%). Of these, two cases had bilateral tumors, one presented with multifocal tumors, two cases had large tumors (>5 cm), and one case, which was diagnosed with a large (5.5 x 4.5 x 4.0 cm) pheochromocytoma, reported early onset of symptoms of the disease (14 yr old). The overall penetrance of pheochromocytoma was 84.6% (11 of 13). Development of medullary thyroid carcinoma in our patients seemed similar to that observed in patients with codon 634 mutations. Haplotype analysis demonstrated that the mutation did not arise from a common ancestor. In vitro studies showed the double C634Y/Y791F RET receptor was significantly more phosphorylated than either activated wild-type receptor or single C634Y and Y791F RET mutants. Conclusions: Our data suggest that the natural history of the novel C634Y/Y791F double mutation carries a codon 634-like pattern of medullary thyroid carcinoma development, is associated with increased susceptibility to unusually large bilateral pheochromocytomas, and is likely more biologically active than each individual mutation. (J Clin Endocrinol Metab 95: 1318-1327, 2010)

The role of p38 mitogen-activated protein kinase in serum-induced leukemia inhibitory factor secretion by bone marrow stromal cells from pediatric myelodysplastic syndromes

Stromal cells from pediatric myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML) associated with MDS(MDS-AML) present high expression of leukemia inhibitor factor (LIF). We demonstrated using mitogen-activated protein kinase ( MAPK) inhibitors that in stromal cells from pediatric MDS and MDS-AML, p38MAPK was critical in serum-induced secretion of LIF. The serum induction of phosphorylated p38MAPK form was observed only in stromal cells from healthy children, whereas in MDS and MDS-AML basal levels were maintained suggesting constitutive p38MAPK activation. Our study suggested the possible importance in pediatric MDS of p38MAPK signaling pathway which may be a future therapeutic target. (C) 2009 Elsevier Ltd. All rights reserved.

Platelet GSK3B activity in patients with late-life depression: Marker of depressive episode severity and cognitive impairment?

Objective. Increased GSK3B activity has been reported as a state marker of major affective episodes in patients with depression and bipolar disorder. No study so far has addressed GSK3B activity in late-life depression. The aims of the present study were to determine GSK3B activity in platelets of elderly patients with major depression, and the association between GSK3B activity and the severity of depressive symptoms and cognitive impairment. Methods. Forty drug-free elderly patients with major depressive episode were compared to healthy older adults (n == 13). Severity of the depressive episode and current cognitive state were determined by the Hamilton Depression Scale (HAM-D) and the Cambridge Cognitive Test (CAMCOG), respectively. Total- and ser-9-phosphorylated GSK3B (tGSK3B and pGSK3B) were determined in platelets by enzyme immunometric assays (EIA). GSK3B activity was indirectly inferred by the GSK3B ratio (i.e. pGSK3B/tGSK3B). Results. Elderly depressed patients had significantly lower pGSK3B levels (P == 0.03) and GSK3B ratio (P == 0.03), indicating higher GSK3B activity. Higher GSK3B activity were observed in patients with severe depressive episode (HAM-D scores > 22, P == 0.03) and with cognitive impairment (CAMCOG scores < 86, P == 0.01). Conclusion. The present findings provide additional evidence of the involvement of GSK3B in the pathophysiology of late-life major depression. Higher GSK3B activity may be more relevant in those patients with more severe depressive symptoms and cognitive impairment.

The Alzheimer`s Association external quality control program for cerebrospinal fluid biomarkers

Background: The cerebrospinal fluid (CSF) biomarkers amyloid beta (A beta)-42, total-tau (T-tau), and phosphorylated-tau (P-tau) demonstrate good diagnostic accuracy for Alzheimer`s disease (AD). However, there are large variations in biomarker measurements between studies, and between and within laboratories. The Alzheimer`s Association has initiated a global quality control program to estimate and monitor variability of measurements, quantify batch-to-batch assay variations, and identify sources of variability. In this article, we present the results from the first two rounds of the program. Methods: The program is open for laboratories using commercially available kits for A beta, T-tau, or P-tau. CSF samples (aliquots of pooled CSF) are sent for analysis several times a year from the Clinical Neurochemistry Laboratory at the Molndal campus of the University of Gothenburg, Sweden. Each round consists of three quality control samples. Results: Forty laboratories participated. Twenty-six used INNOTEST enzyme-linked immunosorbent assay kits, 14 used Luminex xMAP with the INNO-BIA AlzBio3 kit (both measure A beta-(1-42), P-tau(181P), and T-tau), and 5 used Mesa Scale Discovery with the A beta triplex (A beta N-42, A beta N-40, and A beta N-38) or T-tau kits. The total coefficients of variation between the laboratories were 13% to 36%. Five laboratories analyzed the samples six times on different occasions. Within-laboratory precisions differed considerably between biomarkers within individual laboratories. Conclusions: Measurements of CSF AD biomarkers show large between-laboratory variability, likely caused by factors related to analytical procedures and the analytical kits. Standardization of laboratory procedures and efforts by kit vendors to increase kit performance might lower variability, and will likely increase the usefulness of CSF AD biomarkers. (C) 2011 The Alzheimer`s Association. All rights reserved.

Increased platelet GSK3B activity in patients with mild cognitive impairment and Alzheimer`s disease

The disruption of glycogen synthase kinase 3-beta (GSK3B) homeostasis has implications in the pathophysiology of neuropsychiatric disorders, namely Alzheimer`s disease (AD). GSK3B activity is increased within the AD brain, favoring the hyperphosphorylation of microtubule-associated protein Tau and the formation of neurofibrillary tangles. Such abnormality has also been detected in leukocytes of patients with cognitive disorders. The aim of the present study was to determine the expression of total and phosphorylated GSK3B at protein level in platelets of older adults with varying degrees of cognitive impairment, and to compare GSK3B activity in patients with AD, mild cognitive impairment (MCI) and healthy controls. Sixty-nine older adults were included (24 patients with mild to moderate AD, 22 patients with amnestic MCI and 23 elderly controls). The expression of platelet GSK3B (total- and Ser-9 phosphorylated GSK3B) was determined by Western blot. GSK3B activity was indirectly assessed by means of the proportion between phospho-GSK3B to total GSK3B (GSK3B ratio), the former representing the inactive form of the enzyme. Ser-9 phosphorylated GSK3B was significantly reduced in patients with MCI and AD as compared to controls (p = 0.04). Platelet GSK3B ratio was significantly decreased in patients with MCI and AD (p = 0.04), and positively correlated with scores on memory tests (r = 0.298, p = 0.01). In conclusion, we corroborate previous evidence of increased GSK activity in peripheral tissues of patients with MCI and AD, and further propose that platelet GSK may be an alternative peripheral biomarker of this abnormality, provided samples are adequately handled in order to preclude platelet activation. (C) 2010 Elsevier Ltd. All rights reserved.

Posttranslational mechanisms associated with reduced NHE3 activity in adult vs. young prehypertensive SHR

Crajoinas RO, Lessa LMA, Carraro-Lacroix LR, Davel APC, Pacheco BPM, Rossoni LV, Malnic G, Girardi ACC. Posttranslational mechanisms associated with reduced NHE3 activity in adult vs. young prehypertensive SHR. Am J Physiol Renal Physiol 299:F872-F881, 2010. First published July 14, 2010; doi:10.1152/ajprenal.00654.2009.-Abnormalities in renal proximal tubular (PT) sodium transport play an important role in the pathophysiology of essential hypertension. The Na(+)/H(+) exchanger isoform 3 (NHE3) represents the major route for sodium entry across the apical membrane of renal PT cells. We therefore aimed to assess in vivo NHE3 transport activity and to define the molecular mechanisms underlying NHE3 regulation before and after development of hypertension in the spontaneously hypertensive rat (SHR). NHE3 function was measured as the rate of bicarbonate reabsorption by means of in vivo stationary microperfusion in PT from young prehypertensive SHR (Y-SHR; 5-wk-old), adult SHR (A-SHR; 14-wk-old), and age-matched Wistar Kyoto (WKY) rats. We found that NHE3-mediated PT bicarbonate reabsorption was reduced with age in the SHR (1.08 +/- 0.10 vs. 0.41 +/- 0.04 nmol/cm(2)xs), while it was increased in the transition from youth to adulthood in the WKY rat (0.59 +/- 0.05 vs. 1.26 +/- 0.11 nmol/cm(2)xs). Higher NHE3 activity in the Y-SHR compared with A-SHR was associated with a predominant microvilli confinement and a lower ratio of phosphorylated NHE3 at serine-552 to total NHE3 (P-NHE3/total). After development of hypertension, P-NHE3/total increased and NHE3 was retracted out of the microvillar microdomain along with the regulator dipeptidyl peptidase IV (DPPIV). Collectively, our data suggest that the PT is playing a role in adapting to the hypertension in the SHR. The molecular mechanisms of this adaptation possibly include an increase of P-NHE3/total and a redistribution of the NHE3-DPPIV complex from the body to the base of the PT microvilli, both predicted to decrease sodium reabsorption.

Inhibition of phospholipase A(2) in rat brain decreases the levels of total Tau protein

The microtubule-associated protein Tau promotes the assembly and stability of microtubules in neuronal cells. Six Tau isoforms are expressed in adult human brain. All six isoforms become abnormally hyperphosphorylated and form neurofibrillary tangles in Alzheimer disease (AD) brains. In AD, reduced activity of phospholipase A(2) (PLA(2)), specifically of calcium-dependent cytosolic PLA(2) (cPLA(2)) and calcium-independent intracellular PLA(2) (iPLA(2)), was reported in the cerebral cortex and hippocampus, which positively correlated with the density of neurofibrillary tangles. We previously demonstrated that treatment of cultured neurons with a dual cPLA(2) and iPLA(2) inhibitor, methyl arachidonyl fluorophosphonate (MAFP), decreased total Tau levels and increased Tau phosphorylation at Ser(214) site. The aim of this study was to conduct a preliminary investigation into the effects of in vivo infusion of MAFP into rat brain on PLA(2) activity and total Tau levels in the postmortem frontal cortex and dorsal hippocampus. PLA(2) activity was measured by radioenzymatic assay and Tau levels were determined by Western blotting using the anti-Tau 6 isoforms antibody. MAFP significantly inhibited PLA(2) activity in the frontal cortex and hippocampus. The reactivity to the antibody revealed three Tau protein bands with apparent molecular weight of close to 40, 43 and 46 kDa in both brain areas. MAFP decreased the 46 kDa band intensity in the frontal cortex, and the 43 and 46 kDa band intensities in the hippocampus. The results indicate that in vivo PLA(2) inhibition in rat brain decreases the levels of total (nonphosphorylated plus phosphorylated) Tau protein and corroborate our previous in vitro findings.

Involvement of circulating platelets on the hyperalgesic response evoked by carrageenan and Bothrops jararaca snake venom

Background: The role of platelets in hemostasis is well known, but few papers have reported their role in pain and edema induced by inflammatory agents. Objective: To evaluate the role of circulating platelets in the local injury induced by two diverse inflammatory agents, Bothrops jararaca venom (Bjv) and carrageenan. Methods: Rats were (i) rendered thrombocytopenic by administration of polyclonal anti-rat platelet IgG (ARPI) or busulfan, or (ii) treated with platelet inhibitors (aspirin or clopidogrel). Edema formation, local hemorrhage and the pain threshold were assessed after intraplantar injection of Bjv or carrageenan in rat hind paws. Additionally, whole platelets or platelet releasate were tested whether they directly induced hyperalgesia. Results: Platelet counts were markedly diminished in rats administered with either ARPI (+/- 88%) or busulfan (+/- 96%). Previous treatment with ARPI or busulfan slightly reduced edema induced by Bjv or carrageenan. Injection of Bjv, but not of carrageenan, induced a statistically significance increase in hemorrhage in the hind paws of thrombocytopenic rats. Remarkably, hyperalgesia evoked by Bjv or carrageenan was completely blocked in animals treated with ARPI or busulfan, or pre-treated with aspirin or clopidogrel. On the other hand, intraplantar administration of whole platelets or platelet releasate evoked hyperalgesia, which was inhibited by pre-incubation with alkaline phosphatase. Conclusions: Thrombocytopenia or inhibition of platelet function drastically reduced hyperalgesia induced by injection of carrageenan or Bjv; moreover, platelets per se secrete phosphorylated compounds involved in pain mediation. Thus, blood platelets are crucial cells involved in the pain genesis, and their role therein has been underestimated.