Suppression of the release of prostaglandin-like substances by hydrocortisone in vivo

Muscular exercise of the dog's hind leg evokes the release of prostaglandin-like substances / PG-like substances/ into femoral venous blood. The release of PG-like substances detected by the bioassay method was significantly greater in adrenalectomized as compared to normal dogs. To test the possibility that this difference may be related to the deficiency of adrenocortical secretion in adrenalectomized dogs, the effect of hydrocortisone / HC / and aldosterone / AS / upon the release of PG-like substances induced by muscular work of the dog's hind leg was investigated. The doses of HC and AS infused intravenously or intraarterially were close to the range of physiological secretion rate of these hormones. HC suppressed the release of PG-like material by 30 to 60%, whereas AS had no effect upon the rate and duration of the release. The rate of removal of exogenous PGE₂ in the hind limb circulation was not influenced by HC, suggesting that the diminution of PG release by HC results from the suppression of PG generation rather than from the enhancement of degradation. It is suggested that inhibitory effect of HC upon the rate of the release of PG-like substances may be related to the membrane-stabilizing properties of this hormone. The difference in the intensity of the release of PG-like substances between normal and adrenalectomized dogs suggests that, at least in some conditions, the release of endogenous PGs from tissues may be influenced by the state of adrenocortical activity.     

Reference proteome of highly purified human Th1 cells reveals strong effects on metabolism and protein ubiquitination upon differentiation

The differentiation of human CD4⁺ T cells into T helper cell subtypes and regulatory T cells is crucial to the immune response. Among subtypes, Th1 cells are dominant, representing approximately 50% of all lymphocytes. Thus far, most global proteomic studies have used only partially purified T helper cell subpopulations and/or have employed artificial protocols for inducing specific T helper cell subtypes and/or used gel‐based approaches. These studies have shed light on molecular details of certain aspects of the proteome; nevertheless a global analysis of high purity primary naïve and Th1 cells by LC‐MS/MS is required to provide a reference dataset for proteome‐based T cell subtype characterization. The utilization of highly purified Th1 cells for a global proteome assessment and the bioinformatic comparison to naïve cells reveals changes in cell metabolism and the ubiquitination pathway upon T cell differentiation. All MS data have been deposited in the ProteomeXchange with identifier PXD001066 ( http://proteomecentral.proteomexchange.org/dataset/PXD001066 ).     

Compartment resolved reference proteome map from highly purified naïve,activated, effector,and memory CD8+ murine immune cells

Differentiation of CD8⁺ T lymphocytes into effector and memory cells is key for an adequate immune response and relies on complex interplay of pathways that convey signals from the cell surface to the nucleus. In this study, we investigated the proteome of four cytotoxic T‐cell subtypes; naïve, recently activated effector, effector, and memory cells. Cells were fractionated into membrane, cytosol, soluble nuclear, chromatin‐bound, and cytoskeletal compartments. Following LC‐MS/MS analysis, identified peptides were analyzed via MaxQuant. Compartment fractionation and gel‐LC‐MS separation resulted in 2399 proteins identified in total. Comparison between the different subsets resulted in 146 significantly regulated proteins for naïve and effector cells, followed by 116 for activated, and 55 for memory cells. Besides Granzyme B signaling (for activated and/ or effector cells vs. naïve cells), the most prominent changes occurred in the TCA cycle and aspartate degradation. These changes suggest that correct balancing of metabolism is key for differentiation processes. All MS data have been deposited in the ProteomeXchange with identifier PXD001065 ( http://proteomecentral.proteomexchange.org/dataset/PXD001065 ).     

Decreased emodepside sensitivity in unc-49 γ-aminobutyric acid (GABA)-receptor-deficient Caenorhabditis elegans

Emodepside, a semi-synthetic derivative of PF1022A, belongs to a new class of anthelmintic drugs, the cyclooctadepsipeptides, and shows good efficacy against macrocyclic lactone-, levamisole- or benzimidazole-resistant nematode populations. Although putative receptors for emodepside have already been discovered, its mode of action is still not fully understood. The involvement of the γ-aminobutyric acid (GABA)-receptor on the PF1022A mode of action has previously been postulated. Therefore, a possible role of the GABA-receptor, unc-49, in the mode of action of emodepside was investigated using two different Caenorhabditis elegans in vitro assays, a motility assay and a development assay. It was found that there is a clearly reduced sensitivity against emodepside of strains carrying a GABA-receptor, unc-49, loss of function mutation compared with N2 wild type C. elegans. To transfer these results from the model system to parasitic nematodes, the Toxocara canis unc-49B cDNA sequence was identified and used in a rescue experiment. The emodepside-susceptible phenotype could be fully rescued by injection of the T. canis unc-49B cDNA sequence. We believe that this is the first functional rescue of a C. elegans mutant strain with a gene from a clade III parasitic nematode. These findings, together with the earlier data on GABA-receptor binding of PF1022A, suggest that the GABA(A)-receptor UNC-49 is associated with the emodepside mode of action. However, the only partially resistant phenotype of the loss of function mutants indicates that other pathways play a more significant role.     

Morphological and immunophenotypical heterogeneity in breast cancers of young and elderly women

There is a reasonable heterogeneity in the morphological appearance and the immunohistochemical properties of distinct breast tumors. Furthermore, it is also known that cancer arising in young women have different prognosis than the ones developing in the elderly. We analyzed breast tumors of 41 young (<35 years) and 33 older women (>65 years) regarding histopathological properties and immunohistochemical reactions for ER, PgR, HER2 and Ki-67, as well as HER2 FISH. The longest diameters, thus largest available surface areas of the tumors were included in the evaluation. Different regions were marked for morphology and in all immunohistochemical reactions. The regions in the distinct tumors showing different pathological and immunohistochemical appearance were identical (p<0.001). The number of morphologically different tumor regions were more frequent in tumors developing in the young (1.82 vs. 1.48 regions/tumor), and 53.6% of tumors with heterogeneous architecture were in young vs. 39.4% in the elderly. However, regarding HER2 staining, cancers in the young patients have shown greater variability among the different tumor areas (p=0.007). The origin of tumor cells predicting prognosis remains undetermined. Whether the analysis of the expression pattern of the whole tumor is conducted or the minute regions are separately examined and averaged, the same results can be achieved. With the development of molecular techniques and accurate prognostic and treatment information rendered to samples the question may be soon answered.     

Evaluation of sulfatase-directed quinone methide traps for proteomics

Sulfatases hydrolytically cleave sulfate esters through a unique catalytic aldehyde, which is introduced by a posttranslational oxidation. To profile active sulfatases in health and disease, activity-based proteomic tools are needed. Herein, quinone methide (QM) traps directed against sulfatases are evaluated as activity-based proteomic probes (ABPPs). Starting from a p-fluoromethylphenyl sulfate scaffold, enzymatically generated QM-traps can inactivate bacterial aryl sulfatases from Pseudomonas aeruginosa and Klebsiella pneumoniae, and human steroid sulfatase. However, multiple enzyme-generated QMs form, diffuse, and non-specifically label purified enzyme. In complex proteomes, QM labeling is sulfatase-dependent but also non-specific. Thus, fluoromethylphenyl sulfates are poor ABPPs for sulfatases.