Global metabolomics and targeted steroid profiling reveal that rifampin, a strong human PXR activator, alters endogenous urinary steroid markers.

Activation of the pregnane X receptor (PXR) alters the expression of metabolic enzymes and transporters involved in the metabolism of xenobiotics and endobiotics. To identify endogenous biomarkers of PXR activation in humans, rifampin, a strong PXR activator, was administered to 12 healthy male subjects, and their urine was analyzed before and after rifampin administration. Ultraperformance liquid chromatography time-of-flight mass spectrometry (UPLC/QTOF-MS)-based global metabolomics and gas chromatography-mass spectrometry (GC-MS)-based profiling of 75 steroids were used to screen the urine samples. Global metabolomics revealed that hydroxytestosterone sulfate and glycochenodeoxycholate sulfate levels were significantly increased and that androsterone sulfate, dehydroepiandrosterone (DHEA) sulfate, and p-cresol sulfate levels were significantly decreased following rifampin administration compared with controls. Urinary steroid profiling showed that 16α-OH-androstenedione (16α-OH-A-dione), 16α-OH-DHEA, 7α-DHEA, 7ß-DHEA, and 11ß-OH-A-dione levels were increased, whereas DHEA, androsterone, etiocholanolone, estrone, ß-cortolone, and allo-tetrahydrocortisone levels were decreased in the rifampin group. The analysis of the metabolic pathway and the metabolic ratio of steroids enabled the estimation of the induction of CYP1A/3A/7B/11B/2C and the inhibition of CYP17A/19A in response to PXR activation. These human urinary biomarkers may be useful for predicting the extent of PXR activation, monitoring the activity of DMEs, and anticipating drug-drug interactions in patients administered PXR-activating drugs.

Partial two-dimensional gel electrophoresis (2-DE) maps of Streptococcus iniae ATCC29178 and Lactococcus garvieae KG9408.

To examine the proteomes of 2 important causative agents of fish streptococcosis, Streptococcus iniae ATCC29178 and Lactococcus garvieae KG9408, we used 2-dimensional gel electrophoresis (2-DE) followed by mass spectrometry to generate 2-DE maps of these type strains. Silver-stained 2-DE gels of S. iniae ATCC29178 and L. garvieae KG9408 revealed approximately 320 and 300 spots, respectively, and immobilized pH gradient strips (13 cm, pH 4 to 7) revealed that the majority of the detected spots were concentrated in the pH range of 4.5 to 5.5. The spots were randomly selected from the 2-DE profiles and identified by peptide mass fingerprinting using matrix-assisted laser desorption/ionization time of flight mass spectrometry. The majority of the identified proteins were functionally related to energy and carbohydrate metabolism (e.g. enolase ATPase, glyceraldehyde-3-phosphate dehydrogenase) or translation and translocation (e.g. elongation factor G, elongation factor Tu, DNA-directed RNA polymerase alpha chain). These data, along with our partial 2-DE maps of S. iniae ATCC29178 and L. garvieae KG9408, may help suggest antigenic proteins for the development of effective diagnostic tools and vaccines against S. iniae and L. garvieae.

Comparison of proteome and antigenic proteome between two Neospora caninum isolates.

This study was conducted to explore the relationship between two isolates of Neospora caninum (N. caninum) (KBA-2 and VMDL-1) using proteomics. To achieve the goal, proteins of N. caninum tachyzoite lysates of KBA-2 and VMDL-1 were separated by two-dimensional gel electrophoresis (2-DE), stained with silver-nitrate and analyzed using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) to compare protein profiles. In addition, proteins separated by 2-DE were transferred to membranes, probed with bovine anti-N. caninum KBA-2 immunoglobulin G, and reactive proteins were visualized and compared between the two isolates. Most spots on 2-DE profiles and antigenic spots on 2-DE immunoblot profiles were located at similar locations in terms of isoelectric point and molecular weight. Proteins common to both isolates included the following: heat shock protein 70, subtilisin-like serine protease, nucleoside triphosphatase, heat shock protein 60, pyruvate kinase, tubulin alpha, tubulin beta, enolase, putative protein disulfide isomerase, actin, fructase-1,6-bisphosphatase, putative ribosomal protein S2, microneme protein Nc-P38, lactate dihydrogenase, fructose-1,6-bisphosphatase aldolase, serine threonine phosphatase 2C, 14-3-3 protein homologue, N. caninum dense granule-1 and NcGRA2. As a consequence, even though N. caninum KBA-2 and VMDL-1 isolates were isolated from geographically distinct locations there were significant homology in the proteome and antigenic proteome profiles. In addition, proteomic approach was verified as a useful tool for understanding of host immune response against different isolates of protozoa.

Experimental evaluation of pathogenicity of Lactococcus garvieae in black rockfish (Sebastes schlegeli).

Black rockfish (Sebastes schlegeli) is an important mariculture species in Korea. The production of this fish is drastically declined due to bacterial diseases, particularly streptococcosis caused by Lactococcus garvieae. The bacterial surface characteristics of SJ7 and TY6 were found to have capsule but not NB13 and YS18. The experiential evaluation of L. garvieae pathogenicity, the capsular isolates showed high cumulative mortality i.e. SJ7 (100%) and TY6 (60%) compared to non-capsular isolates. Based on this result the capsular isolates L. garvieae were highly suspected as the causative agent of streptococcosis in rockfish.