RTA2 is involved in calcineurin-mediated azole resistance and sphingoid long-chain base release in Candida albicans.

The calcineurin pathway has been reported to be essential for the development of azole resistance in Candida albicans. The depletion or ectopic over-expression of RTA2 increased or decreased susceptibility of C. albicans to azoles, respectively. CaCl(2)- induced activation of the calcineurin pathway in wildtype C. albicans promoted resistance to azoles, while the Ca(2+) chelator (EGTA), calcineurin inhibitors (FK506 and cyclosporin A) and the deletion of RTA2 blocked the resistance-promoting effects of CaCl(2). Furthermore, we found that RTA2 was up-regulated in a calcineurin-dependent manner. The depletion of RTA2 also made the cell membrane of C. albicans liable to be destroyed by azoles and RTA2 over-expression attenuated the destroying effects. Finally, the disruption of RTA2 caused an increased accumulation of dihydrosphingosine (DHS), one of the two sphingolipid long-chain bases, by decreasing release of DHS. In conclusion, our findings suggest that RTA2 is involved in calcineurin-mediated azole resistance and sphingoid long-chain base release in C. albicans.

Symptomatic unruptured isolated middle cerebral artery dissection: clinical and magnetic resonance imaging features.

PURPOSE: Isolated middle cerebral artery dissection (MCAD) is a rare but important clinical entity. The purpose of this study is to demonstrate the clinical and magnetic resonance imaging (MRI) features of symptomatic unruptured isolated MCAD. METHODS: We retrospectively analyzed clinical characteristics and MRI features of eight consecutive ischemic stroke patients diagnosed with unruptured isolated MCAD over a 1-year period. RESULTS: All the patients had symptoms of cerebral infarction, whereas one patient was presented as transient ischemic attack. The most common finding of MCAD on the magnetic resonance angiography (MRA) images was irregular stenosis, found in six patients, followed by double lumen in three, while there was an occlusion in one, as well as stenosis and dilation in one. A total of five of seven patients demonstrated susceptibility vessel signal in the involved segment of MCA on susceptibility-weighted imaging. The high-resolution cross-sectional MRI (hrMRI) delineated intramural hematoma and double lumen in seven patients, respectively, and intimal flap in three, while gadolinium-enhanced T1-weighted images (WI) visualized mural linear or intramural crescentic enhancement in all the patients. In acute and chronic phase, the intramural hematomas appeared isointense or slightly hyperintense or unrecognizable, while gadolinium-enhanced T1WI showed slight to obvious enhancement. Subacute hematomas had a characteristic of crescentic hyperintense on T1- and T2WI. CONCLUSIONS: The presence of unruptured isolated MCAD should be considered when a healthy young subject suffers from a sudden onset of ischemic symptoms or a minor head trauma accompanied by headache. Early MRA with combination of hrMRI precontrast and contrast-enhanced T1-weighted sequence may be helpful in definite diagnosis.

Altered protein profile of lymphocytes in an antigen-specific model of colitis: a comparative proteomic study.

OBJECTIVE: Lymphocytes are deeply involved in the initiation and perpetuation of inflammatory response in inflammatory bowel disease (IBD) and lymphocyte-derived proteins are associated with the pathogenesis of the disease. The aim of this study was to identify the altered protein profiles of lymphocytes from rats with colitis. METHODS: Colitis models were induced by colonic administration of trinitrobenzene sulfonic acid (TNBS) in 50% ethanol in male SD rats. Seven days after administration of TNBS/ethanol, lymphocytes were harvested from mesenteric lymph nodes (MLNs) and proteins were extracted. Two-dimensional polyacrylamide gel electrophoresis and PDQuest 2D-image-analysis software were used to display and analyze the protein spots. The differentially-expressed proteins were identified by tryptic in-gel digestion and mass spectrometry. Real-time RT-PCR was used for selected transcripts to validate the findings of the proteomics analysis. RESULTS: A total of 1,100 protein spots including 26 proteins with at least a two-fold difference in abundance between colitis and control groups were identified. Among all the detected spots, 17 were up-regulated and 9 were down-regulated. It was found that the altered proteins included the regulators of the cell cycle and cell proliferation, signal transduction factors, inflammatory factors, apoptosis-related proteins and metabolic enzymes. CONCLUSIONS: In lymphocytes of rats with TNBS-induced colitis, 26 altered proteins were identified. They involve inflammation, apoptosis, metabolism, and regulation of the cell cycle, cell proliferation, and signal transduction.

Candida albicans THI13 disruption affects production of monocytic cytokines.

INTRODUCTION: The Candida albicansTHI13 gene was identified by its homology to the Candida tropicalis CtNMT1 gene, which is involved in pyrimidine precursor biosynthesis. METHODS: Disruption of THI13 revealed that this gene played a minor role in thiamin biosynthesis in C. albicans. Purified human monocytes were incubated with C. albicans at the optimal Candida: monocyte ratio of 0.5 and cytokines in the supernatants were measured by enzyme-linked immunosorbent assay. RESULTS AND DISCUSSION: This experiment showed that the wild-type strain significantly induced interleukin-10 (IL-10) production but had little effect on IL-12 production, and that THI13 mutants had no significant effect on IL-10 production, though the IL-12 level was increased in the supernatants. These results suggest that THI13 is involved in the host effective immune response by regulating IL-10 and IL-12 production.