Phosphatidylglycerophosphate (PGP) synthase catalyses the committed step in the biosynthesis of phosphatidylglycerol and cardiolipin in mammalian cells. Recently we isolated a Chinese hamster ovary (CHO) PGS1 cDNA encoding PGP synthase. In the present study we purified this PGP synthase to near-homogeneity from the mitochondrial fraction of CHO-K1 cells; the final enzyme preparation gave a sing...

Eosinophils are one of the major mammalian effector cells encountered by helminths during infection. In the present study, we investigated the effects of eosinophil granule exposure on the sheep parasitic nematode Haemonchus contortus as a model. H. contortus eggs exposed to eosinophil granule products showed increased rhodamine 123 efflux and this effect was not due to loss of egg integrity. R...

As a result of the growing availability of genetically engineered mouse lines, the pilocarpine post-status epilepticus (SE) model of temporal lobe epilepsy is increasingly used in mice. A discrepancy in pilocarpine sensitivity in FVB/N wild-type versus P-glycoprotein (PGP)-deficient mice precipitated the investigation of the interaction between pilocarpine and two major multidrug transporters a...

Human endothelial progenitor cells (hEPCs) are promising therapeutic resources for wound repair through stimulating neovascularization. However, the hEPCs-based cell therapy has been hampered by poor engraftment of transplanted cells. In this study, we explored the effects of N-acetylated Proline-Glycine-Proline (Ac-PGP), a degradation product of collagen, on hEPC-mediated cutaneous wound heali...

Previous studies have demonstrated that mitomycin C (MMC) and other DNA cross-linking agents can suppress MDR1 (multidrug resistance 1) gene expression and subsequent functional P-glycoprotein (Pgp) expression, whereas doxorubicin and other anthracyclines increase MDR1 gene expression. In the present study, with stably transfected Madin-Darby canine kidney C7 epithelial cells expressing a human...

BACKGROUND The taxane paclitaxel (Taxol) is often of limited efficacy in chemotherapeutic regimens because some cancer cells express high levels of the efflux pump, P-glycoprotein (Pgp), which removes the drug from the cells. The orally active paclitaxel analog IDN-5109 has been reported to overcome Pgp-mediated drug resistance. We tested whether IDN-5109 acts by modulating Pgp activity. METH...

The reactivity of the ATP-dependent multidrug transporter P-glycoprotein (Pgp) with the conformation-sensitive monoclonal antibody UIC2 is increased in the presence of Pgp transport substrates, ATP-depleting agents, or mutations that reduce the level of nucleotide binding by Pgp. We have investigated the effects of nucleotides and vinblastine, a Pgp transport substrate, on the UIC2 reactivity o...

P-glycoprotein (Pgp), a member of the adenosine triphosphate-binding cassette (ABC) transporter superfamily, is a major drug efflux pump expressed in normal tissues, and is overexpressed in many human cancers. Overexpression of Pgp results in reduced intracellular drug concentration and cytotoxicity of chemotherapeutic drugs and is thought to contribute to multidrug resistance of cancer cells. ...

P-Glycoprotein (Pgp) has been shown to mediate multidrug resistance in tumor cell lines. Overexpression of Pgp has been detected in clinical cancer samples of many histological types. The basis and biological significance of such increases in Pgp expression are not well understood. In this study, the expression of Pgp during stepwise progression to rat liver cancer was examined to investigate t...

Chronic myeloid leukemia blast phase (CML-BP) cells commonly express the multidrug transporter, P-glycoprotein (Pgp). To determine whether Pgp inhibition improves treatment outcome in CML-BP, the Southwest Oncology Group performed a randomized, controlled trial testing the benefit of the Pgp modulator, cyclosporin A (CsA). Seventy-three eligible patients were assigned to treatment with cytarabi...