Dried blood samples (DBSs) have many advantages; yet, impediments have limited the clinical utilization of DBSs. We developed a novel volumetric sampling device that collects a precise volume of blood, which overcomes the heterogeneity and hematocrit issues commonly encountered in a traditional DBS card collection as well as allowing for more efficient extraction and processing procedures and thus, more efficient quantitation, by using the entire sample. We also provided a thorough procedure validation using this volumetric DBS collection device with an established quantitative proteomics analysis method, and then analyzed 1000 proteins using this approach in DBSs concomitantly with serum for future consideration of utility in clinical applications. Our data provide a first step in the establishment of a DBS database for the broad application of this sample type for widespread use in clinical proteomic and other analyses applications.
Hypoxia strongly up-regulates tissue factor and promotes plasma clotting by glioblastoma multiforme, but transcriptional mechanisms remain undefined. Here, we investigated the potential roles of early growth response gene-1 (Egr-1), Sp1, nuclear factor-κB (NF-κB), activator protein-1 (AP-1), and hypoxia-inducible factor-1 (HIF-1) in the hypoxic regulation of tissue factor by glioblastoma multiforme cells in vitro. Hypoxia (1% O2) strongly induced Egr-1 mRNA within 1 hour and led to nuclear localization of Egr-1 protein. Using luciferase reporter plasmids in glioma cells, we found that hypoxia dramatically increased luciferase activity in cells with constructs containing Egr-1-binding sites but not in cells with constructs containing AP-1- or NF-κB-binding sites. Electrophoretic mobility shift assays revealed hypoxia-induced Egr-1, but not Sp1, binding to oligonucleotides containing the Egr-1/Sp1 motif of tissue factor gene promoter. Using an expression vector containing the minimal tissue factor promoter (−111 to +14 bp) and small interfering RNA (siRNA) directed at Egr-1 and Sp1 mRNAs, we found that Egr-1 was required for maximal hypoxic induction of promoter activity. Forced overexpression of Egr-1 but not Sp1 by cDNA transfection caused up-regulation of tissue factor in glioma cells under normoxia (21% O2), whereas siRNA directed at Egr-1 strongly attenuated hypoxia-induced tissue factor expression. To examine the effects of HIF-1α on tissue factor expression, we used glioma cells stably transfected with a HIF-1α siRNA expression vector and found that HIF-1α mRNA silencing did not affect tissue factor expression under hypoxia. We conclude that hypoxic up-regulation of tissue factor in glioblastoma multiforme cells depends largely on Egr-1 and is independent of HIF-1.
Objective: To evaluate neurotrophin (NT) expression in the endometrium of women with and without endometriosis. Design: Prospective, cross-sectional, translational study. Setting: Academic hospital. Patient(s): Thirty-three reproductive-age women undergoing laparoscopy for infertility, pelvic pain, intramural fibroids, or tubal ligation. Intervention(s): Endometrial biopsies, protein microarrays, reverse transcriptase-polymerase chain reaction, ELISAs, and Western blotting. Main Outcome Measure(s): Neurotrophin proteins and mRNAs in eutopic endometrial biopsies. Result(s): Among seven neurotrophic proteins detected on the antibody microarrays, reverse transcriptase-polymerase chain reaction analysis confirmed nerve growth factor, NT-4/5, and brain-derived neurotrophic factor mRNAs in endometrial tissue. Quantitative ELISAs revealed that NT-4/5 (806 ± 701 vs. 256 ± 190 pg/100 mg protein) and brain-derived neurotrophic factor (121 ± 97 vs. 14 ± 11 ng/100 mg protein) concentrations were significantly higher in women with endometriosis. Nerve growth factor (100 ± 74 vs. 93 ± 83 pg/100 mg protein) levels did not differ between cases and controls. Conclusion(s): Neurotrophins are synthesized in situ within the endometrium. NT-4/5 and brain-derived neurotrophic factor proteins were more concentrated in biopsies from endometriosis cases than controls, whereas nerve growth factor levels were similar. We hypothesize that the local production of NTs induces sensory innervation of endometrium of women with endometriosis. These NTs represent novel targets for the diagnosis and treatment of endometriosis.