Effect of vanadate on ATP-induced increase in intracellular calcium ion levels in human umbilical vein endothelial cells

Best time window for the use of calcium-modulating agents to improve functional recovery in injured peripheral nerves-An experiment in rats

Peripheral nerve injury can have a devastating effect on daily life. Calcium concentrations in nerve fibers drastically increase after nerve injury, and this activates downstream processes leading to neuron death. Our previous studies showed that calcium-modulating agents decrease calcium accumulation, which aids in regeneration of injured peripheral nerves; however, the optimal therapeutic window for this application has not yet been identified. In this study, we show that calcium clearance after nerve injury is positively correlated with functional recovery in rats suffering from a crushed sciatic nerve injury. After the nerve injury, calcium accumulation increased. Peak volume is from 2 to 8 weeks post injury; calcium accumulation then gradually decreased over the following 24-week period. The compound muscle action potential (CMAP) measurement from the extensor digitorum longus muscle recovered to nearly normal levels in 24 weeks. Simultaneously, real-time polymerase chain reaction results showed that upregulation of calcium-ATPase (a membrane protein that transports calcium out of nerve fibers) mRNA peaked at 12 weeks. These results suggest that without intervention, the peak in calcium-ATPase mRNA expression in the injured nerve occurs after the peak in calcium accumulation, and CMAP recovery continues beyond 24 weeks. Immediately using calcium-modulating agents after crushed nerve injury improved functional recovery. These studies suggest that a crucial time frame in which to initiate effective clinical approaches to accelerate calcium clearance and nerve regeneration would be prior to 2 weeks post injury. © 2017 Wiley Periodicals, Inc.

Natural vanadium-containing Jeju groundwater inhibits immunoglobulin E-mediated anaphylactic reaction and suppresses eicosanoid generation and degranulation in bone marrow derived-mast cells

The high-affinity receptor for immunoglobulin E (IgE) (FcεRI)-mediated activation of mast cells plays an important role in various allergic diseases. To assess the anti-allergic activity of natural vanadium-containing Jeju groundwater (JW), an in vivo passive cutaneous anaphylaxis (PCA) animal model and in vitro mouse bone marrow-derived mast cells (BMMCs) was used. JW inhibited cyclooxygenase-2 (COX-2)-dependent prostaglandin D(2) (PGD(2)) generation in a dose-dependent manner, with a concomitant reduction of COX-2 protein expression in IgE-induced BMMCs. In addition, JW inhibited 5-lipoxygenase (5-LOX)-dependent generation of leukotriene C(4) (LTC(4)) as well as degranulation in a dose-dependent manner. These results demonstrate that JW has dual COX-2/5-LOX inhibitory activity. In addition, vanadium pentoxide (V(2)O(5)), which is the major vanadium component of JW, also inhibited PGD(2) and LTC(4) generation as well as degranulation in IgE-induced BMMCs. Furthermore, oral administration of JW dose-dependently inhibited mast cell-dependent passive anaphylactic reaction in IgE-sensitized mice. Taken together, these results suggest that JW may be useful in regulating mast cell-mediated allergic response through the suppression of eicosanoid generation and degranulation in mast cells.