Human group II phospholipase A2 in normal and diseased intervertebral discs

AbstractWe measured calcium-dependent phospholipase A2 (PLA2) activity and immunoreactive group II PLA2 levels of 54 normal discs obtained from cadavers and 73 disc samples surgically obtained from patients with spinal disorders, including intervertebral disc herniations, spondylosis, and spondylolisthesis. Both cadaveric and surgical disc specimens contained about two-fold greater PLA2 activity than the ileal mucosa, one of the richest sources of group II PLA2. Discs of middle-aged cases had significantly higher activity than those of younger and elder cases. In cadaveric normal discs, calcium-dependent PLA2 activity was significantly higher in females than in males. Annulus fibrosus and nucleus pulposus contained the same PLA2 levels. In diseases discs, herniated fragments that had extruded or protruded out of the discs possessed lower activity than other parts of discs in the intervertebral space. Immunoreactive group II PLA2 levels of intervertebral discs closely correlated with PLA2 enzymatic activity. We purified a PLA2 from human intervertebral disc to homogeneity to further identify the isozymic nature of discal PLA2. Its NH2-terminal amino acid sequence and molecular weight were identical to those of human group II PLA2. Immunohistochemical analysis using a monoclonal anti-group II PLA2 antibody showed that in both annulus fibrosus and nucleus pulposus chondrocyte contained intense grou II PLA2 immunoreactivity in their cytoplasm, and that the matrix contained no substantial immunoreactivity. These results suggest that group II PLA2 in chondrocytes has important physiological roles in discal ordinary metabolism, maintaining discal homeostasis

Formation and Stability of Interface between Garnet-Type Ta-doped Li7La3Zr2O12 Solid Electrolyte and Lithium Metal Electrode

Garnet-type Li7-xLa3Zr2-xTaxO12 (LLZT) is considered a good candidate for the solid electrolyte in all-solid-state lithium batteries because of its reasonably high conductivity around 10−3 S cm−1 at room temperature and stability against lithium (Li) metal with the lowest redox potential. In this study, we synthesized LLZT with a tantalum (Ta) content of 0.45 via a conventional solid-state reaction process and constructed a Li/LLZT/Li symmetric cell by attaching Li metal foils on the polished top and bottom surfaces of an LLZT pellet. We investigated the influence of heating temperatures and times on the interfacial charge-transfer resistance between LLZT and the Li metal electrode. In addition, the effect of the interface resistance on the stability for Li deposition and dissolution was examined using a galvanostatic cycling test. The lowest interfacial resistance of 25 Ω cm2 at room temperature was obtained by heating at 175 °C (5 °C lower than the melting point of Li) for three to five hours. We confirmed that the current density at which the short circuit occurs in the Li/LLZT/Li cell via the propagation of Li dendrite into LLZT increases with decreasing interfacial charge transfer resistance

Group II phospholipase A2 induced by interleukin-1β in cultured rat gingival fibroblasts

AbstractPreviously, we reported the presence of group II-like phospholipase A2 activity in the soluble fraction of rat gingiva. In the present study, we found that treatment of rat gingival cells with human recombinant interleukin- 1β resulted in dose-dependent stimulation of intracellular and extracellular phospholipase A2 activity. Antisera against group II phospholipase A2 totally blocked the interleukin-1β-induced phospholipase A2 activity, but antisera against group I phospholipase A2 did not. Moreover, immunoblot analysis showed that the induced phospholipase A2 was group II phospholipase A2. These findings suggest that the induced enzyme belongs to the group II phospholipase A2 family of proinflammatory enzymes

Myriad Functions of Stanniocalcin-1 (STC1) Cover Multiple Therapeutic Targets in the Complicated Pathogenesis of Idiopathic Pulmonary Fibrosis (IPF)

Idiopathic pulmonary fibrosis (IPF) is an intractable disease for which the pathological findings are characterized by temporal and spatial heterogeneity. The pathogenesis is composed of myriad factors, including repetitive injuries to epithelial cells, alterations in immunity, the formation of vascular leakage and coagulation, abnormal wound healing, fibrogenesis, and collagen accumulation. Therefore, the molecular target drugs that are used or attempted for treatment or clinical trials may not cover the myriad therapeutic targets of IPF. In addition, the complicated pathogenesis results in a lack of informative biomarkers to diagnose accurately the status of IPF. These facts point out the necessity of using a combination of drugs, that is, each single drug with molecular targets or a single drug with multiple therapeutic targets. In this review, we introduce a humoral factor, stanniocalcin-1 (STC1), which has myriad functions, including the maintenance of calcium homeostasis, the promotion of early wound healing, uncoupling respiration (aerobic glycolysis), reepithelialization in damaged tissues, the inhibition of vascular leakage, and the regulation of macrophage functions to keep epithelial and endothelial homeostasis, which may adequately cover the myriad therapeutic targets of IPF