The overexpression and amplification of HER-2 gene is associated with the malignant biological behavior of ovarian carcinoma and these tumor cells expressing elevated levels of HER-2 appear to be resistant to the cytolysis of NK-92. In this study, we analyzed the cytolysis effects of NK-92 on human ovarian carcinoma cells (SK-OV-3) after inhibition the expression of HER-2 mRNA by siRNA. Human o...

Skeletal muscle makes up 40-50% of body mass, and is thus considered to be a good adult stem cell source for autologous therapy. Although, several stem/progenitor cells have been fractionated from mouse skeletal muscle showing a high potential for therapeutic use, it is unclear whether this is the case in human. Differentiation and therapeutic potential of human skeletal muscle-derived cells (S...

Chemokines are important chemoattractant inflammatory molecules, but their interdependent network in disease pathogenesis remains unclear. Studies in mouse models have shown that herpetic stromal keratitis (SK) is produced by the consequence of a tissue-destructive immunoinflammatory reaction involving herpes simplex virus type 1 (HSV) infection. Here we found that ocular HSV infection leads to...

Sphingosine kinase (SK) catalyses the phosphorylation of sphingosine to generate sphingosine 1-phosphate, which is a second messenger involved in the proliferative responses of mammalian cells. Although the yeast Saccharomyces cerevisiae has similar phosphorylated sphingoid bases which appear to be involved in growth regulation and the response to stress, SK activity had not been previously dem...

Fed-batch culture strategy is often used for increasing production of heterologous recombinant proteins in Escherichia coli. This study was initiated to investigate the effects of dissolved oxygen concentration (DOC), complex nitrogen sources and pH control agents on cell growth and intracellular expression of streptokinase (SK) in recombinant E. coli BL21(DE3). Increase in DOC set point from 3...

The small-conductance K+ channel (SK) in the apical membrane of the cortical-collecting duct (CCD) is regulated by adenosine triphosphate (ATP) and phosphorylation-dephosphorylation processes. When expressed in Xenopus oocytes, ROMK, a cloned K+ channel similar to the native SK channel, can be stimulated by phosphatidylinositol bisphosphate (PIP2), which is produced by phosphoinositide kinases ...

Circulating endothelial progenitor cells (EPCs) are incorporated into foci of neovascularization where they undergo differentiation to mature endothelial cells (ECs). We show here that the enzyme sphingosine kinase-1 (SK-1) regulates the rate and direction of EPC differentiation without effect on the hematopoietic compartment. EPCs have high levels of SK-1 activity, which diminishes with differ...

Small conductance calcium-activated potassium (SK) channels respond to intracellular Ca(2+) via constitutively associated calmodulin (CaM). Previous studies have proposed a modular design for the interaction between CaM and SK channels. The C-lobe and the linker of CaM are thought to regulate the constitutive binding, whereas the N-lobe binds Ca(2+) and gates SK channels. However, we found that...

We used the patch-clamp technique to study the effect of H(2)O(2) on the apical ROMK-like small-conductance K (SK) channel in the cortical collecting duct (CCD). The addition of H(2)O(2) decreased the activity of the SK channels and the inhibitory effect of H(2)O(2) was larger in the CCD from rats on a K-deficient diet than that from rats on a normal-K or a high-K diet. However, application of ...

Small conductance Ca(2+)-activated K(+) channels (SK) regulate action potential (AP) firing properties and excitability in many central neurons. However, the functional roles of SK channels of parasympathetic cardiac motoneurons (PCMNs) in the nucleus ambiguus have not yet been well characterized. In this study, the tracer X-rhodamine-5 (and 6)-isothiocyanate (XRITC) was injected into the peric...