Anterograde trafficking of KCa3.1 in polarized epithelia is Rab1- And Rab8-Dependent and recycling endosome-independent

The intermediate conductance, Ca2+-activated K+ channel (KCa3.1) targets to the basolateral (BL) membrane in polarized epithelia where it plays a key role in transepithelial ion transport. However, there are no studies defining the anterograde and retrograde trafficking of KCa3.1 in polarized epithelia. Herein, we utilize Biotin Ligase Acceptor Peptide (BLAP)-tagged KCa3.1 to address these trafficking steps in polarized epithelia, using MDCK, Caco-2 and FRT cells. We demonstrate that KCa3.1 is exclusively targeted to the BL membrane in these cells when grown on filter supports. Following endocytosis, KCa3.1 degradation is prevented by inhibition of lysosomal/proteosomal pathways. Further, the ubiquitylation of KCa3.1 is increased following endocytosis from the BL membrane and PR-619, a deubiquitylase inhibitor, prevents degradation, indicating KCa3.1 is targeted for degradation by ubiquitylation. We demonstrate that KCa3.1 is targeted to the BL membrane in polarized LLC-PK1 cells which lack the m1B subunit of the AP-1 complex, indicating BL targeting of KCa3.1 is independent of μ1B. As Rabs 1, 2, 6 and 8 play roles in ER/Golgi exit and trafficking of proteins to the BL membrane, we evaluated the role of these Rabs in the trafficking of KCa3.1. In the presence of dominant negative Rab1 or Rab8, KCa3.1 cell surface expression was significantly reduced, whereas Rabs 2 and 6 had no effect. We also co-immunoprecipitated KCa3.1 with both Rab1 and Rab8. These results suggest these Rabs are necessary for the anterograde trafficking of KCa3.1. Finally, we determined whether KCa3.1 traffics directly to the BL membrane or through recycling endosomes in MDCK cells. For these studies, we used either recycling endosome ablation or dominant negative RME-1 constructs and determined that KCa3.1 is trafficked directly to the BL membrane rather than via recycling endosomes. These results are the first to describe the anterograde and retrograde trafficking of KCa3.1 in polarized epithelia cells. © 2014 Bertuccio et al

Developing of corrosion resistance nano copper oxide coating on copper using anodization in oxalate solution

The excellent heat transfer properties of copper it is the reson behind its use in the manufacturing of various equipment of heat transfer applications. However, contamination of water by copper in water circulation systems is one of the serious industrial problems [1]. This contamination commonly results from copper corrosion reactions in boiler feed water environment. The contamination of copper could be reduced by improving copper corrosion resistance in water. This research studies the developing of copper corrosion resistant by using anodization technique. The anodization experiments are conducted in oxalate solutions of concentrations from 0.1 to 0.5 M, at a temperature range from 24 to 0 οC and applied potential from 7.5 to 9 V. Anodized coating was analyzed using field emission scanning microscope, energy dispersive X-ray spectroscopy, and X-ray diffraction. Characterization results referred to the formation of copper oxide anodized coating with grain size range from 25 to 68 nm. The tests of the corrosion resistance of the anodized copper samples were carried out in simulated boiler feed water. The results show the enhancement of corrosion resistance of anodized samples. The corrosion protection efficiencies for the anodized coating increased 86.2% and 74.5% in testing solutions contains 3.5% NaCl, and 2 mg/l NH3, respectively

Study the Influence of the Anodizing Process Parameters on the Anodized Copper Hardness

The metals anodization process used to enhance the surface hardness and corrosion resistance. This study developed a durable hard Nano copper oxide coating on copper using anodization technique in solutions of 0.1 to 0.5 M oxalate concentrations and 0 to 24°C operating temperature. The settings of the process parameters determined by using Taguchi’s experimental design method. The EDX and XRD results confirm the formation of cupric oxide coating with monoclinic lattice crystalline structures. The FESEM results for the coated samples showed that the grain size was in the range between 25 to 68 nm. Microhardness tests for the anodized copper samples characterized by microhardness tester. Analysis of Variance for the orthogonal arrays of Taguchi identified that the most affecting parameter on the microhardness of the coating was the anodizing temperature. The results show that the hardness of the anodized coating was decreased with the anodizing temperature, where maximum hardness, with smaller grain size, were produced at lower anodizing temperatures

Study the Influence of the Anodizing Process Parameters on the Anodized Copper Hardness

The metals anodization process used to enhance the surface hardness and corrosion resistance. This study developed a durable hard Nano copper oxide coating on copper using anodization technique in solutions of 0.1 to 0.5 M oxalate concentrations and 0 to 24°C operating temperature. The settings of the process parameters determined by using Taguchi’s experimental design method. The EDX and XRD results confirm the formation of cupric oxide coating with monoclinic lattice crystalline structures. The FESEM results for the coated samples showed that the grain size was in the range between 25 to 68 nm. Microhardness tests for the anodized copper samples characterized by microhardness tester. Analysis of Variance for the orthogonal arrays of Taguchi identified that the most affecting parameter on the microhardness of the coating was the anodizing temperature. The results show that the hardness of the anodized coating was decreased with the anodizing temperature, where maximum hardness, with smaller grain size, were produced at lower anodizing temperatures

Hypercalcemia, hypercalciuria and nephrocalcinosis in a breast-fed term newborn: A rare presentation

Although hypercalcemia and hypercalciuria are known to occur in breast-fed pre-term infants, to the best of our knowledge, it has never been reported in a term baby previously. We report a term male baby who was followed-up during pregnancy for having bright kidneys, but a follow-up renal ultrasound (US) after birth had revealed normal scan. Laboratory inves-tigations revealed normal serum calcium (Ca), phosphorous (PO 4 ) and alkaline phosphatase (ALP). The baby was being fed by breast milk. Follow-up US two months later showed early nephrocalcinosis along with hypercalcemia and hypercalciuria; by the age of three months, nephrocalcinosis was more extensive and the serum Ca level was more than 12 mg/L with hypercalciuria. Parathyroid hormone (PTH), phosphorous (PO 4 ), ALP and thyroid function tests were all normal. Antenatal history revealed a hypothyroid mother who was maintained on L-thyroxin, calcium and vitamin D supplement during pregnancy. Her blood tests showed normal serum Ca, low PO 4 and elevated PTH. The baby was diagnosed to have hypercalciuria and hypercalcemia secondary to maternal hypophosphatemia (maternal vitamin D deficiency). Breast feeding was stopped and the baby was started on formula, whereby he showed remarkable improvement both for his blood chemistry as well as his hypercalciuria