Milk fat globule EGF factor 8 restores mitochondrial function via integrin-medicated activation of the FAK-STAT3 signaling pathway in acute pancreatitis.

Acute pancreatitis (AP) remains a significant clinical challenge. Mitochondrial dysfunction contributes significantly to the pathogenesis of AP. Milk fat globule EGF factor 8 (MFG-E8) is an opsonizing protein, which has many biological functions via binding to αvß3/5 integrins. Ligand-dependent integrin-FAK activation of STAT3 was reported to be of great importance for maintaining a normal mitochondrial function. However, MFG-E8's role in AP has not been evaluated. METHODS: Blood samples were acquired from 69 healthy controls and 134 AP patients. Serum MFG-E8 levels were measured by ELISA. The relationship between serum concentrations of MFG-E8 and disease severity were analyzed. The role of MFG-E8 was evaluated in experimental models of AP. RESULTS: Serum concentrations of MFG-E8 were lower in AP patients than healthy controls. And serum MFG-E8 concentrations were negatively correlated with disease severity in AP patients. In mice, MFG-E8 administration decreased L-arginine-induced pancreatic injury and mortality. MFG-E8's protective effects in experimental AP were associated with improvement in mitochondrial function and reduction in oxidative stress. MFG-E8 knockout mice suffered more severe pancreatic injury and greater mitochondrial damage after l-arginine administration. Mechanistically, MFG-E8 activated the FAK-STAT3 pathway in AP mice. Cilengitide, a specific αvß3/5 integrin inhibitor, abolished MFG-E8's beneficial effects in AP. PF00562271, a specific FAK inhibitor, blocked MFG-E8-induced STAT3 phosphorylation. APTSTAT3-9R, a specific STAT3 antagonist, also eliminated MFG-E8's beneficial effects under such a condition. CONCLUSIONS: MFG-E8 acts as an endogenous protective mediator in the pathogenesis of AP. MFG-E8 administration protects against AP possibly by restoring mitochondrial function via activation of the integrin-FAK-STAT3 signaling pathway. Targeting the action of MFG-E8 may present a potential therapeutic option for AP.

Calcium Ion Chelation Preserves Platelet Function During Cold Storage.

OBJECTIVE: Platelet transfusion is a life-saving therapy to prevent or treat bleeding in patients with thrombocytopenia or platelet dysfunction. However, for >6 decades, safe and effective strategies for platelet storage have been an impediment to widespread use of platelet transfusion. Refrigerated platelets are cleared rapidly from circulation, precluding cold storage of platelets for transfusion. Consequently, platelets are stored at room temperature with an upper limit of 5 days due to risks of bacterial contamination and loss of platelet function. This practice severely limits platelet availability for transfusion. This study is to identify the mechanism of platelet clearance after cold storage and develop a method for platelet cold storage. Approach and Results: We found that rapid clearance of cold-stored platelets was largely due to integrin activation and apoptosis. Deficiency of integrin ß3 or caspase-3 prolonged cold-stored platelets in circulation. Pretreatment of platelets with EGTA, a cell impermeable calcium ion chelator, reversely inhibited cold storage-induced platelet activation and consequently prolonged circulation of cold-stored platelets. Moreover, transfusion of EGTA-treated, cold-stored platelets, but not room temperature-stored platelets, into the mice deficient in glycoprotein Ibα significantly shortened tail-bleeding times and diminished blood loss. CONCLUSIONS: Integrin activation and apoptosis is the underlying mechanism of rapid clearance of platelets after cold storage. Addition of a cell impermeable calcium ion chelator to platelet products is potentially a simple and effective method to enable cold storage of platelets for transfusion.

Structural, functional, and mechanistic insights uncover the fundamental role of orphan connexin-62 in platelets.

Connexins oligomerise to form hexameric hemichannels in the plasma membrane that can further dock together on adjacent cells to form gap junctions and facilitate intercellular trafficking of molecules. In this study, we report the expression and function of an orphan connexin, connexin-62 (Cx62), in human and mouse (Cx57, mouse homolog) platelets. A novel mimetic peptide (62Gap27) was developed to target the second extracellular loop of Cx62, and 3-dimensional structural models predicted its interference with gap junction and hemichannel function. The ability of 62Gap27 to regulate both gap junction and hemichannel-mediated intercellular communication was observed using fluorescence recovery after photobleaching analysis and flow cytometry. Cx62 inhibition by 62Gap27 suppressed a range of agonist-stimulated platelet functions and impaired thrombosis and hemostasis. This was associated with elevated protein kinase A-dependent signaling in a cyclic adenosine monophosphate-independent manner and was not observed in Cx57-deficient mouse platelets (in which the selectivity of 62Gap27 for this connexin was also confirmed). Notably, Cx62 hemichannels were observed to function independently of Cx37 and Cx40 hemichannels. Together, our data reveal a fundamental role for a hitherto uncharacterized connexin in regulating the function of circulating cells.

Racial differences in α4ß7 expression on CD4+ T cells of HIV-negative men and women who inject drugs.

INTRODUCTION: We performed a cross-sectional study of HIV-uninfected men and women who inject drugs from the ALIVE cohort to examine if black men and women who inject drugs have higher levels of CD4+ T cells expressing the integrin heterodimer α4ß7 compared to white men and women. MATERIALS AND METHODS: Flow cytometry was used to examine expression of α4ß7 and other markers associated with different functional CD4+ T cell subsets in both men and women who inject drugs. RESULTS: Higher levels of α4ß7, CCR5, and CCR6 were observed on CD4+ T cells from black participants compared with white participants. In a multivariable model, α4ß7 expression differed by race, but not sex, age, or other factors. DISCUSSION: Black men and women express higher percentages of α4ß7 expressing CD4+ T cells, which may play a role in HIV disease.

TGFß-mediated expression of TGFß-activating integrins in SSc monocytes: disturbed activation of latent TGFß?

INTRODUCTION: The pathophysiology of systemic sclerosis (SSc) is closely linked to overactive TGFß signaling. TGFß is produced and circulates in latent form, making its activation crucial for signaling. This activation can be mediated via integrins. We investigated the balance between active and latent TGFß in serum of SSc patients and investigated if this correlates with integrin expression on monocytes. METHODS: A TGFß/SMAD3- or BMP/SMAD1/5-luciferase reporter construct was expressed in primary human skin fibroblasts. Both acidified and non-acidified sera of ten SSc patients and ten healthy controls were tested on these cells to determine total and active TGFß and BMP levels respectively. A pan-specific TGFß1/2/3 neutralizing antibody was used to confirm TGFß signaling. Monocytes of 20 SSc patients were isolated using CD14+ positive selection, and integrin gene expression was measured using qPCR. Integrin expression was modulated using rhTGFß1 or a small molecule inhibitor of TGFBR1: SB-505124. RESULTS: SSc sera induced 50% less SMAD3-reporter activity than control sera. Serum acidification increased reporter activity, but a difference between healthy control and SSc serum was no longer observed, indicating that total TGFß levels were not different. Addition of a pan-specific TGFß1/2/3 neutralizing antibody fully inhibited SMAD3-reporter activity of both acidified and not-acidified control and SSc sera. Both HC and SSc sera induced similar SMAD1/5-reporter activity, and acidification increased this, but not differently between groups. Interestingly, expression of two integrin alpha subunits ITGA5 and ITGAV was significantly reduced in monocytes obtained from SSc patients. Furthermore, ITGB3, ITGB5, and ITGB8 expression was also reduced in SSc monocytes. Stimulation of monocytes with TGFß1 induced ITGA5 and ITGAV but lowered ITGB8 expression, whereas the use of the TGFß receptor inhibitor SB-505124 had the opposite effect. CONCLUSION: Total TGFß serum levels are not different between SSc patients and controls, but TGFß activity is. This coincides with a reduced expression of TGFß-activating integrins in monocytes of SSc patients. Because TGFß regulates expression of these integrins in monocytes, a negative feedback mechanism possibly underlies these observations.

Non-classical monocyte homing to the gut via α4ß7 integrin mediates macrophage-dependent intestinal wound healing.

OBJECTIVE: To study the role of α4ß7 integrin for gut homing of monocytes and to explore the biological consequences of therapeutic α4ß7 inhibition with regard to intestinal wound healing. DESIGN: We studied the expression of homing markers on monocyte subsets in the peripheral blood and on macrophage subsets in the gut of patients with IBD and controls with flow cytometry and immunohistochemistry. Integrin function was addressed with dynamic adhesion assays and in vivo gut homing assays. In vivo wound healing was studied in mice deficient for or depleted of α4ß7 integrin. RESULTS: Classical and non-classical monocytes were clearly dichotomous regarding homing marker expression including relevant expression of α4ß7 integrin on human and mouse non-classical monocytes but not on classical monocytes. Monocyte-expressed α4ß7 integrin was functionally important for dynamic adhesion to mucosal vascular addressin cell adhesion molecule 1 and in vivo gut homing. Impaired α4ß7-dependent gut homing was associated with reduced (effect size about 20%) and delayed wound healing and suppressed perilesional presence of wound healing macrophages. Non-classical monocytes in the peripheral blood were increased in patients with IBD under clinical treatment with vedolizumab. CONCLUSION: In addition to reported effects on lymphocytes, anti-α4ß7 therapy in IBD also targets non-classical monocytes. Impaired gut homing of such monocytes might lead to a reduction of wound healing macrophages and could potentially explain increased rates of postoperative complications in vedolizumab-treated patients, which have been observed in some studies.

Predictors of Primary Response to Biologic Treatment [Anti-TNF, Vedolizumab, and Ustekinumab] in Patients With Inflammatory Bowel Disease: From Basic Science to Clinical Practice.

BACKGROUND: Inflammatory bowel diseases [IBD]-ulcerative colitis and Crohn's disease-are commonly treated with biologic drugs. However, only approximately two-thirds of patients have an initial response to these therapies. Personalised medicine has the potential to optimise efficacy, decrease the risk of adverse drug events, and reduce costs by establishing the most suitable therapy for a selected patient. AIM: The present study reviews the potential predictors of short-term primary response to biologic treatment, including not only anti-tumour necrosis factor [TNF] agents [such as infliximab, adalimumab, certolizumab, and golimumab] but also vedolizumab and ustekinumab. METHODS: We performed a systematic bibliographical search to identify studies investigating predictive factors of response to biologic therapy. RESULTS: For anti-TNF agents, most of the evaluated factors have not demonstrated usefulness, and many others are still controversial. Thus, only a few factors may have a potential role in the prediction of the response, including disease behaviour/phenotype, disease severity, C-reactive protein, albumin, cytokine expression in serum, previous anti-TNF therapy, some proteomic markers, and some colorectal mucosa markers. For vedolizumab, the availability of useful predictive markers seems to be even lower, with only some factors showing a limited value, such as the expression of α4ß7 integrin in blood, the faecal microbiota, some proteomic markers, and some colorectal mucosa markers. Finally, in the case of ustekinumab, no predictive factor has been reported yet to be helpful in clinical practice. CONCLUSION: In summary, currently no single marker fulfils all criteria for being an appropriate prognostic indicator of response to any biologic treatment in IBD.

The frequency of circulating integrin α4ß7+ cells correlates with protection against Helicobacter pylori infection in immunized mice.

BACKGROUND: Chronic Helicobacter pylori infection is the cause of peptic ulcers in a subpopulation of individuals and a risk factor for the development of gastric cancer. A vaccine against H pylori infection can prevent the acquisition of the infection and protect against reinfections. Clinical trials to date evaluating the efficacy of H pylori vaccines in human challenge models have shown moderate to poor protection with difficulties in predicting efficacy. Thus, while further studies are needed to design an effective vaccine, we also need to find relevant correlates for vaccine efficacy. OBJECTIVE: To find immune correlates to vaccine efficacy, the frequencies of neutrophils, eosinophils and inflammatory monocytes and CD4+ T-cell memory and mucosa homing integrin α4ß7+ cells were assessed by flow cytometry in the blood of mice after vaccination. MATERIALS AND METHODS: H pylori antigens and cholera toxin or the multiple mutant CT (mmCT) were administered via the sublingual (SL) and intragastric route (IG). The vaccinated mice were infected with H pylori strain SS1 bacteria, and colonization in the stomach and immune responses were evaluated. RESULTS: The H pylori vaccine was effective in reducing bacterial load in the stomach of mice and enhancing immune responses compared to unvaccinated infection controls. In the blood of mice after SL or IG route of vaccination, we observed changes in frequencies of innate and adaptive immune cell subsets compared to infection controls. Remarkably, the frequency of circulating mucosal homing α4ß7+ CD4+ T cells after vaccination correlated with low bacterial load in the stomach of individual mice irrespective of the immunization route. CONCLUSIONS: Our study shows that the innate and adaptive immune cell subsets can be measured in the blood after vaccination and that increased frequency of α4ß7+ CD4+ in the blood after immunization could be used as a predictive marker for the efficacy of vaccine against H pylori infection.

Identification of Candidate Biomarkers Associated with Response to Vedolizumab in Inflammatory Bowel Disease.

BACKGROUND/AIMS: Vedolizumab is an anti-α4ß7 monoclonal antibody approved for the treatment of inflammatory bowel disease (IBD). This exploratory study aimed to identify biomarkers associated with vedolizumab response. METHODS: Twenty-six IBD patients (15 with Crohn's, 11 with ulcerative or indeterminate colitis) initiating vedolizumab at a single center between 2014 and 2016 underwent sampling of serum and peripheral blood mononuclear cells (PBMCs) before and during vedolizumab therapy. Response was defined as steroid-free improvement in endoscopic score or Harvey-Bradshaw index/simple clinical colitis activity index (reduction greater than 3 or total less than 3). PBMCs were evaluated for immunophenotype and expression of α4ß7 integrin on lymphocytes before and during vedolizumab therapy. Serum vedolizumab levels and α4ß7 saturation were measured serially after induction. RESULTS: Fourteen out of 26 (54%) patients treated with vedolizumab responded to therapy. Pretreatment α4ß7 expression was higher in responders on multiple subsets of T, B, and NK cells, with terminal effector memory (p = .0009 for CD4 and .0043 for CD8) and NK cells (p = .0047) best discriminating between responders and nonresponders. During therapy, log10 serum vedolizumab levels at trough were higher in responders than nonresponders (p = .0007). Conversely, the percentage of effector memory T cells with free α4ß7 at trough was lower in responders than nonresponders (p < .0001). However, loss of α4ß7 saturation with vedolizumab was more sensitive to low serum vedolizumab in nonresponders. CONCLUSIONS: Pretreatment α4ß7 expression and α4ß7 receptor saturation during maintenance therapy were identified as candidate biomarkers for vedolizumab response.

Pharmacokinetic and Pharmacodynamic Modeling of Serum Etrolizumab and Circulating ß7 Receptor Occupancy in Patients With Ulcerative Colitis.

Etrolizumab, a humanized monoclonal antibody, specifically binds to the ß7 subunit of the heterodimeric integrins α4ß7 and αEß7. Pharmacokinetic (PK) and pharmacodynamic (PD) data were collected from an etrolizumab phase 1 trial in patients with moderate to severe ulcerative colitis (UC). We developed a mechanism-based model to simultaneously describe the kinetics of serum etrolizumab concentration and free ß7 receptors on circulating intestinal-homing CD4+ T lymphocytes. Included in the analysis were 38 phase 1 UC patients who received single or 3 monthly doses of etrolizumab intravenously or subcutaneously across a dose range of 0.3 to 10 mg/kg. A quasi-steady-state target-mediated drug disposition model was developed to describe the dynamic interaction between serum etrolizumab concentration and free ß7 receptors on intestinal-homing CD4+ T lymphocytes in UC patients. The time profiles of serum etrolizumab and absolute counts of ß7+ lymphocytes (expressed as percentage of baseline level) were well described by the quasi-steady-state target-mediated drug disposition model. The model was able to characterize the maximum drug occupancy of ß7 receptors on intestinal-homing CD4+ T lymphocytes and the concentration-dependent duration of occupancy. The 90% effective concentration for etrolizumab to saturate the ß7 receptors on intestinal homing CD4+ T cells was 1.3 µg/mL. PK and PD profiles predicted by the model were consistent with observations from a subsequent phase 2 study. In conclusion, an integrated PK/PD model developed in this analysis reasonably described serum etrolizumab PK profiles and the relationship between PK and PD (free ß7 receptors on circulating intestinal-homing CD4+ T lymphocytes) in UC patients.

Negative regulators of platelet activation and adhesion.

Platelets are small anucleated cells that constantly patrol the cardiovascular system to preserve its integrity and prevent excessive blood loss where the vessel lining is breached. Their key challenge is to form a hemostatic plug under conditions of high shear forces. To do so, platelets have evolved a molecular machinery that enables them to sense trace amounts of signals at the site of damage and to rapidly shift from a non-adhesive to a pro-adhesive state. However, this highly efficient molecular machinery can also lead to unintended platelet activation and cause clinical complications such as thrombocytopenia and thrombosis. Thus, several checkpoints are in place to tightly control platelet activation and adhesiveness in space and time. In this review, we will discuss select negative regulators of platelet activation, which are critical to maintain patrolling platelets in a quiescent, non-adhesive state and/or to limit platelet adhesion to sites of injury.

Oxidative stress induced modulation of platelet integrin α2bß3 expression and shedding may predict the risk of major bleeding in heart failure patients supported by continuous flow left ventricular assist devices.

INTRODUCTION: Oxidative stress and platelet integrin α2bß3 plays important role in the process of hemostasis and thrombosis. We hypothesized that device-induced patient specific oxidative stress and integrin α2bß3 shedding may be linked to major bleeding complication (MBC) in heart failure (HF) patients supported by continuous flow left ventricular assist devices (CF-LVADs). MATERIALS AND METHODS: We recruited 47patients implanted with CF-LVADs and 15 healthy volunteers. Fourteen patients developed MBC (bleeder group) within one month after implantation while others were considered non-bleeder group (n=33). Oxidative stresses were evaluated by measuring reactive oxygen species (ROS) in platelets, superoxide dismutase (SOD) activity, total antioxidant capacity (TAC) and oxidized low density lipoprotein (oxLDL). Assessments of α2bß3 were carried out using flow cytometry and ELISA. RESULTS: Biomarkers of oxidative stress and α2bß3 shedding (decreased surface expression and higher plasma levels) were found to be preexisting condition in all HF patients prior to CF-LVAD implantation compared to the healthy volunteers. Significantly elevated levels of ROS and oxLDL; concomitant depletion of SOD and TAC; and α2bß3 shedding were observed in the bleeder group temporarily in comparison to the non-bleeder group after CF-LVAD implantation. A significantly strong association between α2bß3 shedding and biomarkers of oxidative stress was observed; suggesting a potential role of oxidative stress in platelet integrin shedding leading to MBC after CF-LVAD implantation. Moreover, a receiver operating characteristic (ROC) analysis indicated that the likelihood of MBC data from Integrin α2bß3 shedding had a predictive power of MBC in CF-LVAD patients. CONCLUSIONS: Oxidative stress might play a potential role in accelerating α2bß3 shedding and platelet dysfunction, resulting in MBC in CF-LVAD patients. Integrin α2bß3 shedding may be used to refine bleeding risk stratification in CF-LVAD patients.

Inner Mitochondrial Membrane Disruption Links Apoptotic and Agonist-Initiated Phosphatidylserine Externalization in Platelets.

OBJECTIVE: Phosphatidylserine exposure mediates platelet procoagulant function and regulates platelet life span. Apoptotic, necrotic, and integrin-mediated mechanisms have been implicated as intracellular determinants of platelet phosphatidylserine exposure. Here, we investigate (1) the role of mitochondrial events in platelet phosphatidylserine exposure initiated by these distinct stimuli and (2) the cellular interactions of the procoagulant platelet in vitro and in vivo. APPROACH AND RESULTS: Key mitochondrial events were examined, including cytochrome c release and inner mitochondrial membrane (IMM) disruption. In both ABT-737 (apoptotic) and agonist (necrotic)-treated platelets, phosphatidylserine externalization was temporally correlated with IMM disruption. Agonist stimulation resulted in rapid cyclophilin D-dependent IMM disruption that coincided with phosphatidylserine exposure. ABT-737 treatment caused rapid cytochrome c release, eventually followed by caspase-dependent IMM disruption that again closely coincided with phosphatidylserine exposure. A nonmitochondrial and integrin-mediated mechanism has been implicated in the formation of a novel phosphatidylserine-externalizing platelet subpopulation. Using image cytometry, this subpopulation is demonstrated to be the result of the interaction of an aggregatory platelet and a procoagulant platelet rather than indicative of a novel intracellular mechanism regulating platelet phosphatidylserine externalization. Using electron microscopy, similar interactions between aggregatory and procoagulant platelets are demonstrated in vitro and in vivo within a mesenteric vein hemostatic thrombus. CONCLUSIONS: Platelet phosphatidylserine externalization is closely associated with the mitochondrial event of IMM disruption identifying a common pathway in phosphatidylserine-externalizing platelets. The limited interaction of procoagulant platelets and integrin-active aggregatory platelets identifies a potential mechanism for procoagulant platelet retention within the hemostatic thrombus.

DioxolaneA3-phosphatidylethanolamines are generated by human platelets and stimulate neutrophil integrin expression.

Activated platelets generate an eicosanoid proposed to be 8-hydroxy-9,10-dioxolane A3 (DXA3). Herein, we demonstrate that significant amounts of DXA3 are rapidly attached to phosphatidylethanolamine (PE) forming four esterified eicosanoids, 16:0p, 18:0p, 18:1p and 18:0a/DXA3-PEs that can activate neutrophil integrin expression. These lipids comprise the majority of DXA3 generated by platelets, are formed in ng amounts (24.3±6.1ng/2×108) and remain membrane bound. Pharmacological studies revealed DXA3-PE formation involves cyclooxygenase-1 (COX), protease-activated receptors (PAR) 1 and 4, cytosolic phospholipase A2 (cPLA2), phospholipase C and intracellular calcium. They are generated primarily via esterification of newly formed DXA3, but can also be formed in vitro via co-oxidation of PE during COX-1 co-oxidation of arachidonate. All four DXA3-PEs were detected in human clots. Purified platelet DXA3-PE activated neutrophil Mac-1 expression, independently of its hydrolysis to the free eicosanoid. This study demonstrates the structures and cellular synthetic pathway for a family of leukocyte-activating platelet phospholipids generated on acute activation, adding to the growing evidence that enzymatic PE oxidation is a physiological event in innate immune cells.

Enhanced gut homing receptor expression of unswitched memory B cells in rheumatoid arthritis.

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Blood cell integrins and diseases.

Integrins are adhesion molecules on the surface of cells. In blood cells they are responsible for rapid changes during adhesion of the cell to the endothelium. Deficiency or defective function of integrins will result in severe illnesses. Surprisingly, certain variants of integrins are associated with an increased risk of developing SLE. In autoimmune diseases and as a result of organ transplantations integrins participate in reactions in which leukocytes attack the body's own tissues. This has resulted in the development of drugs in antibody form for inhibition of the action of integrins. These drugs may, however, exhibit severe adverse effects.

Omega 3 (n-3) fatty acids down-regulate nuclear factor-kappa B (NF-κB) gene and blood cell adhesion molecule expression in patients with homozygous sickle cell disease.

Chronic inflammation and reduced blood levels of omega-3 fatty acids (n-3) are known characteristics of sickle cell disease (SCD).The anti-inflammatory properties of n-3 fatty acids are well recognized. Omega-3 treated (n = 24), hydroxyurea (HU) treated (n = 18), and n-3 untreated (n=21) homozygous SCD patients (HbSS) and healthy (HbAA) controls (n = 25) matched for age (5-16 years), gender and socioeconomic status were studied. According to age (5-10) or (11-16) years, two or three capsules containing 277.8 mg docosahexaenoic (DHA) and 39.0mg eicosapentaenoic (EPA) or high oleic acid placebo (41%) were assigned to n-3 treated and n-3 untreated groups, respectively. Hydroxyurea treated group was on dosage more than 20 mg/kg/day. The effect of supplementation on systemic and blood cell markers of inflammation was investigated. The n-3 treated group had higher levels of DHA and EPA (p < 0.001) and lower white blood cell count and monocyte integrin (p < 0.05) compared with the n-3 untreated. No difference was detected between the two groups regarding C-reactive protein, granulocytes integrin and selectin, plasma tumour necrosis factor-α and interleukin-10. The n-3 treated group had lowered nuclear factor-kappa B (NF-κB) gene expression compared to n-3 untreated and HU treated groups (p < 0.05). This study provides evidence that supplementation with n-3 fatty acids may ameliorate inflammation and blood cell adhesion in patients with SCD.

Bioactive factors in uteroplacental and systemic circulation link placental ischemia to generalized vascular dysfunction in hypertensive pregnancy and preeclampsia.

Preeclampsia is a pregnancy-associated disorder characterized by hypertension, and could lead to maternal and fetal morbidity and mortality; however, the pathophysiological mechanisms involved are unclear. Predisposing demographic, genetic and environmental risk factors could cause localized abnormalities in uteroplacental cytoactive factors such as integrins, matrix metalloproteinases, cytokines and major histocompatibility complex molecules leading to decreased vascular remodeling, uteroplacental vasoconstriction, trophoblast cells apoptosis, and abnormal development of the placenta. Defective placentation and decreased trophoblast invasion of the myometrium cause reduction in uteroplacental perfusion pressure (RUPP) and placental ischemia/hypoxia, an important event in preeclampsia. RUPP could stimulate the release of circulating bioactive factors such as the anti-angiogenic factors soluble fms-like tyrosine kinase-1 and soluble endoglin that cause imbalance with the pro-angiogenic factors vascular endothelial growth factor and placental growth factor, or cause the release of inflammatory cytokines, reactive oxygen species, hypoxia-induced factor-1 and AT1 angiotensin receptor agonistic autoantibodies. The circulating bioactive factors target endothelial cells causing generalized endotheliosis, endothelial dysfunction, decreased vasodilators such as nitric oxide and prostacyclin and increased vasoconstrictors such as endothelin-1 and thromboxane A2, leading to increased vasoconstriction. The bioactive factors also stimulate the mechanisms of VSM contraction including Ca(2+), protein kinase C, and Rho-kinase and induce extracellular matrix remodeling leading to further vasoconstriction and hypertension. While therapeutic options are currently limited, understanding the underlying mechanisms could help design new interventions for management of preeclampsia.

A signature for immune response correlates with HCV treatment outcome in Caucasian subjects.

Broad proteomic profiling was performed on serum samples of phase 2 studies (PROVE1, PROVE2, and PROVE3) of the direct-acting antiviral drug telaprevir in combination with peg-interferon and ribavirin in subjects with HCV. Using only profiling data from subjects treated with peg-interferon and ribavirin, a signature composed of pretreatment levels of 13 components was identified that correlated well (R(2)=0.68) with subjects' underlying immune response as measured by week 4 viral decline and was highly predictive of sustained virologic response in non-African American subjects (AUC=0.99). The signature was validated by predicting in an independent cohort of non-African American subjects treated with telaprevir, peg-interferon and ribavirin (AUC=0.854). Samples from extreme responders were over-represented in these analyses. Proteins identified as differentially-expressed between responders and non-responders to HCV treatment were quantified using multiple reaction monitoring in samples from all Caucasian subjects in the peg-interferon and ribavirin arms of PROVE1 and PROVE2, revealing 15 proteins that were significantly differentially expressed between treatment responders and non-responders. Seven of the proteins are part of focal adhesions or other macromolecular assemblies that form structural links between integrins and the actin cytoskeleton and are involved in antiviral response. BIOLOGICAL SIGNIFICANCE: HCV is a significant health problem. We describe a novel approach for identifying markers that predicts HCV treatment response different treatment regimens and use this approach to identify a novel HCV treatment response signature. The signature has potential to guide optimization of HCV treatment regimens.