Proteomic Response of Human Umbilical Vein Endothelial Cells to Histamine Stimulation

The histamine receptors (HRs) represent a subclass of G protein‐coupled receptors (GPCRs) and comprise four subtypes. Due to their numerous physiological and pathological effects, HRs are popular drug targets for the treatment of allergic reactions or the regulation of gastric acid secretion. Hence, an understanding of the functional selectivity of HR ligands has gained importance. These ligands can bind to specific GPCRs and selectively activate defined pathways. Supporting the activation of a therapeutically necessary pathway without the activation of other signaling cascades can result in drugs with more specific activity and fewer side effects. To evaluate the cellular consequences resulting from receptor binding, comprehensive analyses of cellular protein alterations upon incubation with ligands are required. For this purpose, endothelial cells are treated with histamine, as the endogenous ligand of HRs, to obtain a global overview of its cellular effects. Quantitative proteomics and pathway analyses of histamine‐treated and untreated cells reveal enrichment of the nuclear factor‐κB and tumor necrosis factor signaling pathways, cytokine?cytokine receptor interactions, complement and coagulation cascades, and acute inflammatory processes upon histamine treatment. This strategy offers the opportunity to monitor HR‐mediated signaling in a multidimensional manner.     

Identification of muscle specific ring finger proteins as potential regulators of the titin kinase domain

The giant myofibrillar protein titin contains within its C-terminal region a serine-threonine kinase of unknown function. We have identified a novel muscle specific RING finger protein, referred to as MURF-1, that binds in vitro to the titin repeats A168/A169 adjacent to the titin kinase domain. In myofibrils, MURF-1 is present within the periphery of the M-line lattice in close proximity to titin's catalytic kinase domain, within the Z-line lattice, and also in soluble form within the cytoplasm. Yeast two-hybrid screens with MURF-1 as a bait identified two other highly homologous MURF proteins, MURF-2 and MURF-3. MURF-1,2,3 proteins are encoded by distinct genes, share highly conserved N-terminal RING domains and in vitro form dimers/heterodimers by shared coiled-coil motifs. Of the MURF family, only MURF-1 interacts with titin repeats A168/A169, whereas MURF-3 has been reported to affect microtubule stability. Association of MURF-1 with M-line titin may potentially modulate titin's kinase activity similar to other known kinase-associated proteins, whereas differential expression and heterodimerization of MURF1, 2 and 3 may link together titin kinase and microtubule-dependent signal pathways in striated muscles.     

Antioxidant superoxide dismutase activity in obese children

The aim of the study was to evaluate the antioxidative Cu/Zn-SOD (superoxide dismutase) response to obesity-related stress in obese children compared to a similar-aged control group. Forty-eight exogenic obese children and 11 healthy children were compared for red cell Cu/Zn-SOD, glucose, and lipid profiles and the relations between the were investigated. Antioxidant response as Cu/Zn-SOD was significantly higher in the obese group (p<0.05). Although glucose and lipid levels were statistically higher in the obese group, a certain relation with the SOD level was not established in childhood. This is the first study showing the oxidative stress caused by obesity and related antioxidative response even in the childhood period. Interventions, including diet modifications, should be kept in mind to diminish the obesity-related oxidative stress from the childhood period.     

Exaggerated TSH responses to TRH in patients with goiter and 'normal' basal TSH levels

BACKGROUND/AIM: The availability of sensitive thyrotropin (TSH) assays decreased the diagnostic value of thyrotropin-releasing hormone stimulation tests (TRH-ST) in subclinical hypothyroidism. In this study we aimed to evaluate the relation between basal and stimulated serum TSH levels on TRH-ST and to determine the prevalence of patients with normal basal serum TSH and exaggerated TSH responses. METHODS: 179 patients (117 girls, 123 pubertal) with a median age of 12 (2.7-21.4) years who presented with goiter were enrolled and evaluated for their pubertal stage, height, thyroid autoimmunity, ultrasonography, thyroid function, and TRH-ST. Serum TSH concentrations were determined by sensitive assays. At TRH-ST, a peak serum TSH level >25 mIU/l was considered as an exaggerated response. RESULTS: 30 (17%) patients had an exaggerated TSH response. In patients with serum TSH levels between 2 and 4.68 mIU/l (upper half the normal range), an exaggerated TSH response was observed in 19.5%. A positive correlation between basal and TRH-stimulated TSH levels was determined (r = 0.536, p < 0.01). In patients with an exaggerated TSH response, 23 had normal (discordant) and 7 had high basal TSH levels (concordant). The mean basal serum TSH level was lower in the discordant group compared to the concordant group (p < 0.01). CONCLUSION: Basal serum TSH levels might not be sufficient for diagnosing subclinical hypothyroidism. Stimulated TSH levels on TRH-ST are valuable, especially when serum TSH concentrations are in the upper half of the normal range.     

The role of the PTEN/mTOR axis in clinical response of rectal cancer patients

Background

Preoperative chemoradiotherapy has long been accepted as a method to improve survival and lifetime quality of rectal cancer patients. However, physiologic effects of these therapies largely depend on the resistance of cells to the radiation, type of chemotherapeutic agents and individual responses. As one of the signaling cascades involved in chemo- or radiation- resistance, the present study focused on several proteins involved in pTEN/Akt/mTOR pathway to explore their prognostic significance.

Materials and methods

Samples from advanced stage rectal cancer patients were analyzed to detect expression levels of pTEN/Akt/mTOR pathway related proteins pTEN, mLST8, REDD1, BNIP3, SAG and NOXA, together with p53, by RT-qPCR. Kaplan–Meier analysis was used to assess expression-survival relation and correlations among all proteins and clinicopathological features were statistically analyzed.

Results.

Except p53, none of the proteins showed prognostic significance. High p53 expression presented clear impact on overall survival and disease free survival. It was also significantly related to pathologic complete response. p53 showed high correlation to local recurrence as well. On the other hand, strong correlation was observed with PTEN expression and tumor response, but not with survival. High associations were also observed between mLST8/REDD1, PTEN and NOXA, confirming their role in the same cascade.

Conclusion

The contentious role of p53 as a prognostic biomarker in colorectal cancer was further affirmed, while PTEN and REDD1 could be suggested as potential candidates. Additionally, NOXA emerges as a conjunctive element for different signaling pathways.

     

Effect of cobalt-60 (γ radiation) on multidrug-resistant multiple myeloma cell lines

Emergence of resistance to chemotherapy and radiotherapy is a major obstacle for the successful treatment of MM (multiple myeloma). Prednisone, vincristine and melphalan are commonly used chemotherapeutic agents for the treatment of MM. In the current study, we examined the presence of possible cross-resistance between these drugs and gamma (γ) radiation. Prednisone, vincristine and melphalan resistant RPMI-8226 and U-266 MM cells were generated by stepwise increasing concentrations of the drugs. The sensitive and resistant cells were exposed to 200- and 800 cGy γ radiation, and proliferation was examined by XTT {2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide} assay. The results showed that Prednisone- and melphalan-resistant RPMI-8226 cells were also cross-resistant to 200 and 800 cGy γ radiation application, while vincristine-resistant cells did not show resistance. On the other hand, Prednisone-, vincristine- and melphalan-resistant U-266 cells showed cross-resistance to 200- and 800 cGy γ radiation application. These results demonstrated that MM cells resistant to anticancer agents respond to radiation in different levels. These findings may be important in the clinical applications of radiation therapy in the treatment of vincristine resistant MM.     

Data shopping in an open marketplace: Introducing the Ontogrator web application for marking up data using ontologies and browsing using facets

In the future, we hope to see an open and thriving data market in which users can find and select data from a wide range of data providers. In such an open access market, data are products that must be packaged accordingly. Increasingly, eCommerce sellers present heterogeneous product lines to buyers using faceted browsing. Using this approach we have developed the Ontogrator platform, which allows for rapid retrieval of data in a way that would be familiar to any online shopper. Using Knowledge Organization Systems (KOS), especially ontologies, Ontogrator uses text mining to mark up data and faceted browsing to help users navigate, query and retrieve data. Ontogrator offers the potential to impact scientific research in two major ways: 1) by significantly improving the retrieval of relevant information; and 2) by significantly reducing the time required to compose standard database queries and assemble information for further research. Here we present a pilot implementation developed in collaboration with the Genomic Standards Consortium (GSC) that includes content from the StrainInfo, GOLD, CAMERA, Silva and Pubmed databases. This implementation demonstrates the power of ontogration and highlights that the usefulness of this approach is fully dependent on both the quality of data and the KOS (ontologies) used. Ideally, the use and further expansion of this collaborative system will help to surface issues associated with the underlying quality of annotation and could lead to a systematic means for accessing integrated data resources.