Estrogen-related receptor ␣ (ERR␣) is one of the first orphan nuclear receptors to be identified, yet its physiological functions are still unclear. We show here that ERR␣ is an effector of the transcriptional coactivator PGC-1␣ [peroxisome proliferator-activated receptor ␥ (PPAR␥) coactivator 1␣], and that it regulates the expression of genes involved in oxidative phosphorylation and mitochondrial biogenesis. Inhibition of ERR␣ compromises the ability of PGC-1␣ to induce the expression of genes encoding mitochondrial proteins and to increase mitochondrial DNA content. A constitutively active form of ERR␣ is sufficient to elicit both responses. ERR␣ binding sites are present in the transcriptional control regions of ERR␣͞PGC-1␣-induced genes and contribute to the transcriptional response to PGC-1␣. The ERR␣-regulated genes described here have been reported to be expressed at reduced levels in humans that are insulin-resistant. Thus, changes in ERR␣ activity could be linked to pathological changes in metabolic disease, such as diabetes. E strogen-related receptor ␣ (ERR␣, NR3B1) was identified on the basis of its sequence similarity to classical, hormoneregulated steroid receptors (1). Based on its ability to recognize similar DNA sequences as the estrogen receptors, ERR␣ has been proposed to modulate estrogen signaling (2-5). ERR␣ may also regulate bone formation, given that it is highly expressed at ossification sites, promotes osteoblast differentiation in vitro, and activates the promoter of the bone matrix protein osteopontin (6, 7). Finally, ERR␣ may regulate fatty acid oxidation. Consistent with this function, ERR␣ is prominently expressed in tissues with high capacity for ␤-oxidation of fatty acids, such as brown fat, heart, muscle, and kidney, and induces the expression of the medium-chain acyl-CoA dehydrogenase gene (8,9).A better understanding of the transcriptional programs and cellular pathways that depend on ERR␣ has been hampered by the lack of tools to regulate the activity of this receptor. Despite the high similarity between ERR␣ and other ligand-dependent nuclear receptors, it is not clear whether ERR␣ activity is regulated by small lipophilic ligands. Compounds that inhibit ERR␣-dependent transcription, such as toxaphene, chlordane, and diethylstilbestrol, have been described (10, 11). However, these compounds are not specific enough for ERR␣ to facilitate studies of its cellular function. Recently, we demonstrated that the transcriptional coactivator peroxisome proliferator-activated receptor ␥ (PPAR␥) coactivator 1␣ (PGC-1␣) regulates ERR␣ function (12). PGC-1␣ induces the expression of ERR␣ and interacts physically with ERR␣, enabling it to activate transcription (12, 13). These findings suggest that PGC-1␣ can be used as a protein ''ligand'' to regulate ERR␣-dependent transcription and study ERR␣ function.PGC-1␣ has been identified as a tissue-specific coactivator of nuclear receptors (14-16). The expression of PGC-1␣ is most prominent in tissues with high energy demands, similar to the ex...

Abundant evidence suggests that a unifying principle governing the molecular pathology of cancer is the co-dependent aberrant regulation of core machinery driving proliferation and suppressing apoptosis. Anomalous proteins engaged in support of this tumorigenic regulatory environment most probably represent optimal intervention targets in a heterogeneous population of cancer cells. The advent of RNA-mediated interference (RNAi)-based functional genomics provides the opportunity to derive unbiased comprehensive collections of validated gene targets supporting critical biological systems outside the framework of preconceived notions of mechanistic relationships. We have combined a high-throughput cell-based one-well/one-gene screening platform with a genome-wide synthetic library of chemically synthesized small interfering RNAs for systematic interrogation of the molecular underpinnings of cancer cell chemoresponsiveness. NCI-H1155, a human non-small-cell lung cancer line, was employed in a paclitaxel-dependent synthetic lethal screen designed to identify gene targets that specifically reduce cell viability in the presence of otherwise sublethal concentrations of paclitaxel. Using a stringent objective statistical algorithm to reduce false discovery rates below 5%, we isolated a panel of 87 genes that represent major focal points of the autonomous response of cancer cells to the abrogation of microtubule dynamics. Here we show that several of these targets sensitize lung cancer cells to paclitaxel concentrations 1,000-fold lower than otherwise required for a significant response, and we identify mechanistic relationships between cancer-associated aberrant gene expression programmes and the basic cellular machinery required for robust mitotic progression.

Ten percent of deaths worldwide are due to trauma, and it is the third most common cause of death in the United States. Despite a profound upregulation in procoagulant mechanisms, one-quarter of trauma patients present with laboratory-based evidence of trauma-induced coagulopathy (TIC), which is associated with poorer outcomes including increased mortality. The most common causes of death after trauma are hemorrhage and traumatic brain injury (TBI). The management of TIC has significant implications in both because many hemorrhagic deaths could be preventable, and TIC is associated with progression of intracranial injury after TBI. This review covers the most recent evidence and advances in our understanding of TIC, including the role of platelet dysfunction, endothelial activation, and fibrinolysis. Trauma induces a plethora of biochemical and physiologic changes, and despite numerous studies reporting differences in coagulation parameters between trauma patients and uninjured controls, it is unclear whether some of these differences may be “normal” after trauma. Comparisons between trauma patients with differing outcomes and use of animal studies have shed some light on this issue, but much of the data continue to be correlative with causative links lacking. In particular, there are little data linking the laboratory-based abnormalities with true clinically evident coagulopathic bleeding. For these reasons, TIC continues to be a significant diagnostic and therapeutic challenge.

BackgroundThe endothelial glycocalyx layer (EGL) is a key regulator of vascular permeability, cell adhesion, and inflammation. The EGL is primarily composed of syndecan-1, hyaluronic acid (HA), heparan sulfate (HS) and chondroitin sulfate (CS). While many studies have observed increased shedding of syndecan-1 during hemorrhagic shock, little is known about the shedding of other EGL components, and their effects on altered permeability and coagulation. We characterized shedding of all four primary components of the EGL, as well as the plasma’s effect on permeability and thrombin generation in a cohort of trauma patients.MethodsPlasma samples were collected from 5 healthy consented volunteers and 22 severely injured trauma patients upon admission to the emergency department. ELISA assays were performed to quantify shed HA, HS, CS and syndecan-1 in plasma. A colloid osmometer and Electric Cell-substrate Impedance Sensing (ECIS) system were used to measure plasma colloid osmotic pressure (COP) and cell permeability, respectively. Thrombin generation was measured using a calibrated automated thrombogram (CAT). Initial vital signs, routine laboratory values, and injury severity scores (ISS) were recorded. Non-parametric statistical tests were used to compare differences between groups.ResultsWe observed increased shedding of all four proteins in trauma patient plasma compared to healthy controls: 31.7 vs. 21.2 U/L of CS, 175.8 vs. 121.9 ng/ml of HS, 946.7 vs. 618.6 ng/ml of HA and 245.8 vs. 31.6 ng/ml of syndecan-1 (all p < 0.05). Patients with low plasma COP (≤16 mmHg) had significantly increased syndecan-1 and HA compared to those with normal COP, which corresponded to increased cell permeability via ECIS. CS and HS did not vary between COP groups. Lastly, patients with low COP displayed reduced peak thrombin generation of less than 250 nM on average (p < 0.05).ConclusionsGlycocalyx components were shed more in trauma patients compared to healthy controls in this cohort. However, only syndecan-1 and HA shedding were significantly higher in patients with reduced plasma COP. Thrombin generation was impaired in patients with low plasma COP. These data suggest that low plasma COP correlates well to glycocalyx degradation and thrombin loss following trauma, which consequently affect permeability and coagulation.

IntroductionThe link between cancer and venous thromboembolism (VTE) is referred to as Trousseau syndrome. Interestingly, different cancer types are associated with different rates of VTE, with pancreatic cancer having one of the highest rates. 1,2 A VTE risk-scoring model has been developed that stratifies ambulatory cancer patients undergoing chemotherapy into 3 VTE risk categories based on 5 parameters: (1) the site of the primary tumor, (2) prechemotherapy leukocyte count, (3) platelet count, (4) hemoglobin level, and (5) body mass index. 3 Recently, this model was expanded to include the biomarkers D-dimer and soluble P-selectin. 4 Another potential circulating biomarker of VTE risk in pancreatic cancer patients is microparticle (MP) tissue factor (TF). [5][6][7][8][9] Full-length TF (flTF) is a transmembrane protein that activates the coagulation cascade. 10 In addition, an alternatively spliced form of TF (asTF) has been identified that lacks a membrane anchor and therefore can be released as a soluble protein. 11 Increased TF expression is correlated with poor prognosis in pancreatic cancer. [12][13][14] Cultured human pancreatic tumor lines express variable levels of both flTF and asTF and release TF-positive MPs containing flTF into the culture medium. [14][15][16][17][18][19] In some patients with pancreatic cancer, high levels of TF-positive MPs are found in the circulation and, in a small pilot study, were predictive of VTE. [5][6][7]9,20 In a mouse model of human colorectal tumors, human TF protein is released into the circulation. 21 In nude mice bearing orthotopic human pancreatic tumors (L3.6pl) plasma levels of human TF protein were correlated with the levels of thrombin-antithrombin (TAT) complex, a marker of the activation of coagulation. 22 Further, plasma from these tumor-bearing mice was found to enhance thrombin generation in vitro in a human TF-dependent manner. 22 Another study found that human (SOJ-4) and mouse (PANC02) pancreatic cell lines expressed TF, and the investigators observed an accumulation of tumor-derived MPs at the site of thrombosis and increased thrombosis in a microvascular model. 18 The objective of the present study was to determine the role of tumor-derived TF in the activation of coagulation and thrombosis in a xenograft mouse model of human pancreatic tumors. We found that only TF-positive tumors activated coagulation and that this activation was abolished by inhibition of human TF. Two TF-positive pancreatic tumor cell lines activated coagulation, but only one had detectable levels of circulating TF-positive MPs, which suggested that activation of coagulation was due to TF expression by the tumor itself rather than to TF on the MPs. Mice with elevated levels of TF-positive MPs exhibited increased thrombosis in a saphenous vein model, but not in an inferior vena cava (IVC) stenosis model. Methods Cell linesHuman pancreatic (MIAPaCa-2 [CRL-1420] Abs and proteinsPE-labeled mouse IgG control (#555574), mouse anti-human TF (#550312) and FITC-conjugated anti-human MUC...

Epidemiologic studies have correlated elevated plasma fibrinogen (hyperfibrinogenemia) with risk of cardiovascular disease and arterial and venous thrombosis. However, it is unknown whether hyperfibrinogenemia is merely a biomarker of the proinflammatory disease state or is a causative mechanism in the etiology. We raised plasma fibrinogen levels in mice via intravenous infusion and induced thrombosis by ferric chloride application to the carotid artery (high shear) or saphenous vein (lower shear); hyperfibrinogenemia significantly shortened the time to occlusion in both models. Using immunohistochemistry, turbidity, confocal microscopy, and elastometry of clots produced in cell and tissue factor-initiated models of thrombosis, we show that hyperfibrinogenemia increased thrombus fibrin content, promoted faster fibrin formation, and increased fibrin network density, strength, and stability. Hyperfibrinogenemia also increased thrombus resistance to tenecteplase-induced thrombolysis in vivo. These data indicate that hyperfibrinogenemia directly promotes thrombosis and thrombolysis resistance and does so via enhanced fibrin formation and stability. These findings strongly suggest a causative role for hyperfibrinogenemia in acute thrombosis and have significant implications for thrombolytic therapy. Plasma fibrinogen levels may be used to identify patients at risk for thrombosis and inform thrombolytic administration for treating acute thrombosis/thromboembolism. IntroductionElevated plasma fibrinogen is associated with risk of cardiovascular disease and arterial and venous thrombosis. [1][2][3][4][5][6][7][8][9] Several studies have detected dose effects, with increased risk of death or thrombosis in subjects with the highest plasma fibrinogen concentrations. [6][7][8][9] The Framingham 7 and Fragmin During Instability in Coronary Artery Disease 8 studies positively correlated fibrinogen levels with risk of cardiovascular disease and incidence of death and/or myocardial infarction, respectively. The Leiden Thrombophilia Study showed that persons with elevated fibrinogen levels (4.0-4.9 vs Ͻ 3.0 mg/mL, 130%-160% of normal) have an adjusted odds ratio for venous thrombosis of 1.6, whereas persons with Ն 5 mg/mL fibrinogen (Ն 170% of normal) have a 4-fold higher thrombotic risk, even after adjusting for C-reactive protein levels. 9 These epidemiologic studies suggest that elevated fibrinogen is an independent risk factor for both arterial and venous thrombosis and therefore a potential diagnostic and therapeutic target for predicting and reducing thrombosis.Importantly, however, epidemiologic studies have not and cannot show a causal relationship between fibrinogen and disease etiology. 2,10,11 Fibrinogen levels increase with age, inflammatory processes, hematocrit, hypertension, glucose intolerance, cigarette smoking, and adiposity, and high fibrinogen levels increase plasma viscosity, a demonstrated risk factor for coronary heart disease. 5,6,12 These potential confounders have not permitted distinction between fibr...

A syndecan-1 level ≥40 ng/mL identified patients with significantly worse outcomes, despite admission physiology similar to those without the condition.

Key Points• Early platelet administration is associated with improved hemostasis and reduced mortality in severely injured, bleeding trauma patients.Transfusing platelets during massive hemorrhage is debated because of a lack of high-quality evidence concerning outcomes in trauma patients. The objective of this study was to examine the effect of platelet transfusions on mortality in severely injured trauma patients. This work analyzed PROPPR (Pragmatic, Randomized Optimal Platelet and Plasma Ratios) trial patients who received only the first cooler of blood products, which either did or did not contain platelets. Primary outcomes were all-cause mortality at 24 hours and 30 days and hemostasis.Secondary outcomes included cause of death, complications, and hospital-, intensive care unit (ICU)-, and ventilator-free days. Continuous variables were compared using Wilcoxon rank sum tests. Categorical variables were compared using Fisher's exact tests. There were 261 PROPPR patients who achieved hemostasis or died before receiving a second cooler of blood products (137 received platelets and 124 did not). Patients who received platelets also received more total plasma (median, 3 vs 2 U; P , .05) by PROPPR intervention design.There were no differences in total red blood cell transfusions between groups. After controlling for plasma volume, patients who received platelets had significantly decreased 24-hour (5.8% vs 16.9%; P , .05) and 30-day mortality (9.5% vs 20.2%; P , .05). More patients in the platelet group achieved hemostasis (94.9% vs 73.4%; P , .01), and fewer died as a result of exsanguination (1.5% vs 12.9%; P , .01). Patients who received platelets had a shorter time on mechanical ventilation (P , .05); however, no differences in hospital-or ICU-free days were observed. In conclusion, early platelet administration is associated with improved hemostasis and reduced mortality in severely injured, bleeding patients. This trial was registered at www.clinicaltrials.gov as # NCT01545232.