Vanadium Compounds : Their Action on Alkaline Phosphatase Activity

The direct effect of different vanadium compounds upon alkaline phosphatase (ALP) activity was investigated~ Vanadate and vanadyl inhibited both the soluble and particulate ALP activity from UMR.106 cells and front bovine intestinal ALP. We have also shown the inhibition of ALP activity in the soluble fraction of osteoblasts by peroxo and hydroperoxo vanadium compounds. ALP activity in the particulate fraction was not inhibited by these species; nor was the bovine intestinal ALP. Using inhibitors of Tyr-phosphatase (PTPases), the soluble ALP was partially characterized as a PTPase. The major activity in the particulate fraction represents the bone-specific ALPactivity. This study demonstrates that different forms of vanadium are direct inhibitors of ALP activity. This effect is dependent on the enzymatic activity investigated and on the origin of the ALP.Facultad de Ciencias Médica

Proliferative and morphological changes induced by vanadium compounds on Swiss 3T3 fibroblasts

Vanadium compounds are shown to have a mitogenic effect on fibroblast cells. The effects of vanadate, vanadyl and pervanadate on the proliferation and morphological changes of Swiss 3T3 cells in culture are compared. Vanadium derivatives induced cell proliferation in a biphasic manner, with a toxic-like effect at doses over 50 mM, after 24 h of incubation. Vanadyl and vanadate were equally potent at 2.5–10 mM. At 50 mM vanadate inhibited cell proliferation, whereas slight inhibition was observed at 100 mM of vanadyl. At 10 mM pervanadate was as potent as vanadate and vanadyl in stimulating fibroblast proliferation, but no effect was observed at lower concentrations. A pronounced cytotoxic-like effect was induced by pervanadate at 50 mM. All of these effects were accompanied by morphological changes: transformation of fibroblast shape from polygonal to fusiform; retraction with cytoplasm condensation; and loss of lamellar processes. The magnitude of these transformations correlates with the potency of vanadium derivatives to induce a cytotoxic-like effect: pervanadate > vanadate > vanadyl. These data suggest that the oxidation state and coordination geometry of vanadium determine the degree of the cytotoxicit

Vanadium Compounds : Their Action on Alkaline Phosphatase Activity

The direct effect of different vanadium compounds upon alkaline phosphatase (ALP) activity was investigated~ Vanadate and vanadyl inhibited both the soluble and particulate ALP activity from UMR.106 cells and front bovine intestinal ALP. We have also shown the inhibition of ALP activity in the soluble fraction of osteoblasts by peroxo and hydroperoxo vanadium compounds. ALP activity in the particulate fraction was not inhibited by these species; nor was the bovine intestinal ALP. Using inhibitors of Tyr-phosphatase (PTPases), the soluble ALP was partially characterized as a PTPase. The major activity in the particulate fraction represents the bone-specific ALPactivity. This study demonstrates that different forms of vanadium are direct inhibitors of ALP activity. This effect is dependent on the enzymatic activity investigated and on the origin of the ALP.Facultad de Ciencias Médica

Synthesis, characterization and bioactivity of a new VO2q/Aspirin complex

A new VO2q complex with salicylic acid acetate (Aspirin) of formula C18H18Cl2O12V2 was synthesized and characterized. Its biological effects upon cell proliferation, differentiation and promotion of tyrosine protein phosphorylation have been tested in two lines of osteoblastlike cells in culture

Vanadium Compounds

The direct effect of different vanadium compounds upon alkaline phosphatase (ALP) activity was investigated~ Vanadate and vanadyl inhibited both the soluble and particulate ALP activity from UMR.106 cells and front bovine intestinal ALP. We have also shown the inhibition of ALP activity in the soluble fraction of osteoblasts by peroxo and hydroperoxo vanadium compounds. ALP activity in the particulate fraction was not inhibited by these species; nor was the bovine intestinal ALP. Using inhibitors of Tyr-phosphatase (PTPases), the soluble ALP was partially characterized as a PTPase. The major activity in the particulate fraction represents the bone-specific ALPactivity. This study demonstrates that different forms of vanadium are direct inhibitors of ALP activity. This effect is dependent on the enzymatic activity investigated and on the origin of the ALP

Tyrosine phosphorylation and morphological transformation induced by four vanadium compounds on MC3T3E1 cells

The present study was performed to determine the phosphotyrosine-protein levels induced by insulin and by four vanadium derivatives in MC3T3E1 osteoblast-like cells. We have also attempted to associate these patterns with the vanadium-induced growth and morphological changes of such cells. Vanadate (Vi), vanadyl (VO), bis(maltolato)oxovanadium (IV) (BMOV) and bis(maltolato)dioxovanadium (V) (BMV) stimulate cell growth in a narrow range of concentration, but are also inhibitors for the cells at high concentrations. Vanadium-treated cells displayed clear changes in their morphology after overnight incubation. However, BMV was the least cytotoxic and the weakest inducer of morphological changes. All the compounds promote the phosphorylation of tyrosine residues in several proteins. This effect was more pronounced at low than at high doses. At low doses (10 μM), BMV showed a phosphorylation pattern similar to that of insulin, while Vi, VO and BMOV induced strong phosphorylation of cell proteins. The present findings suggest that the vanadium-induced growth regulation and morphological changes in MC3T3E1 osteoblast-like cells are associated with the ability of these agents to increase the phosphotyrosine protein levels and to inhibit phosphotyrosine phosphatases. These properties are dependent on the oxidation state as well as on the organic ligand which coordinates the vanadium atom

The European/International Fibromuscular Dysplasia Registry and Initiative (FEIRI)-clinical phenotypes and their predictors based on a cohort of 1000 patients

AIMS: Since December 2015, the European/International Fibromuscular Dysplasia (FMD) Registry enrolled 1022 patients from 22 countries. We present their characteristics according to disease subtype, age and gender, as well as predictors of widespread disease, aneurysms and dissections.METHODS AND RESULTS: All patients diagnosed with FMD (string-of-beads or focal stenosis in at least one vascular bed) based on CTA, MRA and/or catheter-based angiography were eligible.Patients were predominantly women (82%) and Caucasians (88%). Age at diagnosis was 46\ub116 years (12% 6565yo), 86% were hypertensive, 72% had multifocal and 57% multivessel FMD. Compared to patients with multifocal FMD, patients with focal FMD were younger, more often men, had less often multivessel FMD but more revascularizations. Compared to women with FMD, men were younger, had more often focal FMD and arterial dissections. Compared to younger patients with FMD, patients 6565yo had more often multifocal FMD, lower eGFR and more atherosclerotic lesions. Independent predictors of multivessel FMD were age at FMD diagnosis, stroke, multifocal subtype, presence of aneurysm or dissection and family history of FMD. Predictors of aneurysms were multivessel and multifocal FMD. Predictors of dissections were age at FMD diagnosis, male gender, stroke and multivessel FMD.CONCLUSIONS: The European/International FMD Registry allowed large-scale characterization of distinct profiles of patients with FMD and, more importantly, identification of a unique set of independent predictors of widespread disease, aneurysms and dissections, paving the way for targeted screening, management and follow-up of FMD.TRANSLATIONAL PERSPECTIVE: Fibromuscular dysplasia (FMD) is nowadays considered as a systemic arterial disease, warranting brain-to-pelvis vascular imaging in all patients. However, most current evidence is derived from a limited number of expert centres. Furthermore, one size may not fit all. Based on analysis of the first thousand patients enrolled in the European/International FMD registry (46 centres; 22 countries) we characterized distinct patient profiles according to FMD subtype, age and gender and identified predictors of widespread disease, aneurysms and dissections, paving the way for individualized management and follow-up. Further studies will allow refining patient characterization according to ethnicity, genetic profile and imaging biomarkers