Ways of coping and biomarkers of an increased atherothrombotic cardiovascular disease risk in elderly individuals

Objective. To investigate the relationship between coping and atherothrombotic biomarkers of an increased cardiovascular disease (CVD) risk in the elderly. Methods. We studied 136 elderly caregiving and noncaregiving men and women who completed the Ways of Coping Checklist to assess problem-focused coping, seeking social support (SSS), blamed self, wishful thinking, and avoidance coping. They had circulating levels of 12 biomarkers measured. We also probed for potential mediator and moderator variables (chronic stress, affect, health behavior, autonomic activity) for the relation between coping and biomarkers. Results. After controlling for demographic and CVD risk factors, greater use of SSS was associated with elevated levels of serum amyloid A (P = 0.001), C-reactive protein (CRP) (P = 0.002), vascular cellular adhesion molecule (VCAM)-1 (P = 0.021), and D-dimer (P = 0.032). There were several moderator effects. For instance, greater use of SSS was associated with elevated VCAM-1 (P < 0.001) and CRP (P = 0.001) levels in subjects with low levels of perceived social support and positive affect, respectively. The other coping styles were not significantly associated with any biomarker. Conclusions. Greater use of SSS might compromise cardiovascular health through atherothrombotic mechanisms, including elevated inflammation (i.e., serum amyloid A, CRP, VCAM-1) and coagulation (i.e., D-dimer) activity. Moderating variables need to be considered in this relationship.

Responsiveness and habituation of soluble icam-1 to acute psychosocial stress in men: determinants and efect of stress-hemoconcentration

We studied the psychophysiology of soluble intercellular adhesion molecule-1 (sICAM-1) in 25 apparently healthy middle-aged men who underwent an acute psychosocial stressor three times with one week apart. Measures of the biological stress response were obtained at week one and three. The magnitude of the sICAM-1 stress response showed no habituation between visits. At week one, cognitive stress appraisal independently predicted integrated sICAM-1 area under the curve (AUC) between rest, immediately post-stress, and 45 min and 105 min post-stress (beta=.67, p=.012, deltaR(2)=.41). Diastolic blood pressure AUC (beta=-.45, p=.048, deltaR(2)=.21) and heart rate (AUC) (beta=.44, p=.055, deltaR(2)=.21) were independent predictors of sICAM-1 (AUC) at week three. Adjustment for hemoconcentration yielded a decrease in sICAM-1 levels from rest to post-stress (p<.001). Stress responsiveness of plasma sICAM-1 was predicted by stress perception and hemodynamic reactivity and affected by stress-hemoconcentration but unrelated to cortisol reactivity and not readily adapting to stress repeats.

Chronic excessive erythrocytosis induces endothelial activation and damage in mouse brain

Excessive erythrocytosis results in severely increased blood viscosity, which may have significant detrimental effects on endothelial cells and, ultimately, function of the vascular endothelium. Because blood-brain barrier stability is crucial for normal physiological function, we used our previously characterized erythropoietin-overexpressing transgenic (tg6) mouse line (which has a hematocrit of 0.8-0.9) to investigate the effect of excessive erythrocytosis on vessel number, structure, and integrity in vivo. These mice have abnormally high levels of nitric oxide (NO), a potent proinflammatory molecule, suggesting altered vascular permeability and function. In this study, we observed that brain vessel density of tg6 mice was significantly reduced (16%) and vessel diameter was significantly increased (15%) compared with wild-type mice. Although no significant increases in vascular permeability under normoxic or acute hypoxic conditions (8% O2 for 4 h) were detected, electron-microscopic analysis revealed altered morphological characteristics of the tg6 endothelium. Tg6 brain vascular endothelial cells appeared to be activated, with increased luminal protrusions reminiscent of ongoing inflammatory processes. Consistent with this observation, we detected increased levels of intercellular adhesion molecule-1 and von Willebrand factor, markers of endothelial activation and damage, in brain tissue. We propose that chronic excessive erythrocytosis and sustained high hematocrit cause endothelial damage, which may, ultimately, increase susceptibility to vascular disease.

Longitudinal data on telomere length in leukocytes from newborn baboons support a marked drop in stem cell turnover around 1 year of age

Stem cells of various tissues are typically defined as multipotent cells with 'self-renewal' properties. Despite the increasing interest in stem cells, surprisingly little is known about the number of times stem cells can or do divide over a lifetime. Based on telomere-length measurements of hematopoietic cells, we previously proposed that the self-renewal capacity of hematopoietic stem cells is limited by progressive telomere attrition and that such cells divide very rapidly during the first year of life. Recent studies of patients with aplastic anemia resulting from inherited mutations in telomerase genes support the notion that the replicative potential of hematopoietic stem cells is directly related to telomere length, which is indirectly related to telomerase levels. To revisit conclusions about stem cell turnover based on cross-sectional studies of telomere length, we performed a longitudinal study of telomere length in leukocytes from newborn baboons. All four individual animals studied showed a rapid decline in telomere length (approximately 2-3 kb) in granulocytes and lymphocytes in the first year after birth. After 50-70 weeks the telomere length appeared to stabilize in all cell types. These observations suggest that hematopoietic stem cells, after an initial phase of rapid expansion, switch at around 1 year of age to a different functional mode characterized by a markedly decreased turnover rate.

The cell surface receptor FGFRL1 forms constitutive dimers that promote cell adhesion

FGFRL1 is a novel member of the fibroblast growth factor (FGF) receptor family. Utilizing the FRET (fluorescence resonance energy transfer) technique, we demonstrate that FGFRL1 forms constitutive homodimers at cell surfaces. The formation of homodimers was verified by co-precipitation of differentially tagged FGFRL1 polypeptides from solution. If overexpressed in cultivated cells, FGFRL1 was found to be enriched at cell-cell contact sites. The extracellular domain of recombinant FGFRL1 promoted cell adhesion, but not cell spreading, when coated on plastic surfaces. Adhesion was mediated by heparan sulfate glycosaminoglycans located at the cell surface. It could specifically be blocked by addition of soluble heparin but not by addition of other glycosaminoglycans. When the amino acid sequence of the putative heparin-binding site was modified by in vitro mutagenesis, the resulting protein exhibited decreased affinity for heparin and reduced activity in the cell-binding assay. Moreover, a synthetic peptide corresponding to the heparin-binding site was able to neutralize the effect of heparin. With its dimeric structure and its adhesion promoting properties, FGFRL1 resembles the nectins, a family of cell adhesion molecules found at cell-cell junctions.

Metabolic predictors of inflammation, adhesion, and coagulability in healthy younger-aged adults

Elevated levels of inflammatory biomarkers are associated with the pathophysiology of cardiovascular diseases and are predictors of cardiovascular events. The objective of this study was to determine the unique contributions of metabolic factors as predictors of inflammation (C-reactive protein (CRP) and interleukin-6 (IL-6)), adhesion (soluble intercellular adhesion molecule-1 (sICAM-1)), and coagulation (D-dimer) in healthy younger-aged adults. Participants were 83 women and 92 men (mean age 30.04 years, s.d. +/- 4.8, range 22-39) of normal weight to moderate obese weight (mean BMI 24.4 kg/m(2), s.d. +/- 3.35, range 17-32). The primary data analytical approaches included Pearson correlation and multiple linear regression. Circulating levels of CRP, IL-6, sICAM-1, and D-dimer were determined in plasma. Higher levels of CRP were independently associated with higher BMI, a greater waist-to-hip ratio, female gender, and higher triglycerides (P < 0.001). Higher IL-6 levels were independently associated with a greater waist-to-hip ratio (P < 0.01). Higher levels of sICAM-1 were independently associated with higher BMI, higher triglycerides, and lower insulin resistance (P < 0.001). Higher D-dimer levels were independently associated with higher BMI and being female (P < 0.001). Having a higher BMI was most consistently associated with elevated biomarkers of inflammation, adhesion, and coagulation in this sample of healthy younger-aged adults, although female gender, insulin resistance, and lipid levels were also related to the biomarkers. The findings provide insight into the adverse cardiovascular risk associated with elevated body weight in younger adults.

Predictors of inflammation in response to anthracycline-based chemotherapy for breast cancer

Although chemotherapy for breast cancer can increase inflammation, few studies have examined predictors of this phenomenon. This study examined potential contributions of demographics, disease characteristics, and treatment regimens to markers of inflammation in response to chemotherapy for breast cancer. Thirty-five women with stage I-III-A breast cancer (mean age 50 years) were studied prior to cycle 1 and prior to cycle 4 of anthracycline-based chemotherapy. Circulating levels of inflammatory markers with high relevance to breast cancer were examined, including C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-alpha), Interleukin-1 receptor antagonist (IL1-RA), vascular endothelial growth factor (VEGF), soluble intercellular adhesion molecule-1 (sICAM-1), Interleukin- (IL-6), soluble P-selectin (sP-selectin), and von Willebrand factor (vWf). Chemotherapy was associated with elevations in VEGF (p < or = 0.01), sICAM-1 (p < or = 0.01), sP-selectin (p < or = 0.02) and vWf (p < or = 0.05). Multiple regression analysis controlling for age and body mass index (BMI) showed that higher post-chemotherapy levels of inflammation were consistently related to higher pre-chemotherapy levels of inflammation (ps < or =0.05) as well as to certain disease characteristics. Post-chemotherapy IL-6 levels were higher in patients who had larger tumors (p < or = 0.05) while post-chemotherapy VEGF levels were higher in patients who had smaller tumors (p < or = 0.05). Post-chemotherapy sP-selectin levels were highest in women who had received epirubicin, cytoxan, 5-fluorouracil chemotherapy (p < or = 0.01). These findings indicate that chemotherapy treatment can be associated with elevations in certain markers of inflammation, particularly markers of endothelial and platelet activation. Inflammation in response to chemotherapy is most significantly related to inflammation that existed prior to chemotherapy but also potentially to treatment regimen and to certain disease characteristics.

EpCAM-targeted delivery of nanocomplexed siRNA to tumor cells with designed ankyrin repeat proteins

Specific delivery to tumors and efficient cellular uptake of nucleic acids remain major challenges for gene-targeted cancer therapies. Here we report the use of a designed ankyrin repeat protein (DARPin) specific for the epithelial cell adhesion molecule (EpCAM) as a carrier for small interfering RNA (siRNA) complementary to the bcl-2 mRNA. For charge complexation of the siRNA, the DARPin was fused to a truncated human protamine-1 sequence. To increase the cell binding affinity and the amount of siRNA delivered into cells, DARPin dimers were generated and used as fusion proteins with protamine. All proteins expressed well in Escherichia coli in soluble form, yet, to remove tightly bound bacterial nucleic acids, they were purified under denaturing conditions by immobilized metal ion affinity chromatography, followed by refolding. The fusion proteins were capable of complexing four to five siRNA molecules per protamine, and fully retained the binding specificity for EpCAM as shown on MCF-7 breast carcinoma cells. In contrast to unspecific LipofectAMINE transfection, down-regulation of antiapoptotic bcl-2 using fusion protein complexed siRNA was strictly dependent on EpCAM binding and internalization. Inhibition of bcl-2 expression facilitated tumor cell apoptosis as shown by increased sensitivity to the anticancer agent doxorubicin.

Cleavage of extracellular matrix in periodontitis: gingipains differentially affect cell adhesion activities of fibronectin and tenascin-C

Gingipains are cysteine proteases that represent major virulence factors of the periodontopathogenic bacterium Porphyromonas gingivalis. Gingipains are reported to degrade extracellular matrix (ECM) of periodontal tissues, leading to tissue destruction and apoptosis. The exact mechanism is not known, however. Fibronectin and tenascin-C are pericellular ECM glycoproteins present in periodontal tissues. Whereas fibronectin mediates fibroblast adhesion, tenascin-C binds to fibronectin and inhibits its cell-spreading activity. Using purified proteins in vitro, we asked whether fibronectin and tenascin-C are cleaved by gingipains at clinically relevant concentrations, and how fragmentation by the bacterial proteases affects their biological activity in cell adhesion. Fibronectin was cleaved into distinct fragments by all three gingipains; however, only arginine-specific HRgpA and RgpB but not lysine-specific Kgp destroyed its cell-spreading activity. This result was confirmed with recombinant cell-binding domain of fibronectin. Of the two major tenascin-C splice variants, the large but not the small was a substrate for gingipains, indicating that cleavage occurred primarily in the alternatively spliced domain. Surprisingly, cleavage of large tenascin-C variant by all three gingipains generated fragments with increased anti-adhesive activity towards intact fibronectin. Fibronectin and tenascin-C fragments were detected in gingival crevicular fluid of a subset of periodontitis patients. We conclude that cleavage by gingipains directly affects the biological activity of both fibronectin and tenascin-C in a manner that might lead to increased cell detachment and loss during periodontal disease.

Cell surface $\beta$-1,4-galactosyltransferase function during invasion and metastasis

Metastasis is the complex process of tumor cell spread which is responsible for the majority of cancer-related deaths. Metastasis necessitates complex phenotypic changes, many of which are mediated by changes in the activities of cell surface molecules. One of these is cell surface $\beta$1,4-galactosyltransferase (GalTase), which is elevated on more highly metastatic cells. In this study, both molecular and biochemical methods were used to perturb and manipulate cell surface GalTase levels on K1735 murine melanoma cell lines in order to examine its function in metastasis.^ As expected, highly metastatic K1735 variants have higher cell surface GalTase than poorly metastatic variants. Stably transfected K1735 cell lines that overexpress surface GalTase were created. These cell lines were assayed for metastatic ability using an invasion chamber with Matrigel-coated filter inserts. Cells with increased surface GalTase were uniformly more invasive than neo transfected controls. With multiple cell lines, there was a direct correlation (r = 0.918) between surface GalTase activity and invasiveness. Homologous recombination was used to create K1735 cells with decreased levels of surface GalTase. These cells were uniformly less invasive than controls. Cell surface GalTase was inhibited using two different biochemical strategies. In both cases, inhibition of surface GalTase led to a decrease in in vivo metastatic ability of K1735 cells. This is the first direct experimental evidence addressing GalTase function in metastasis. These data provide several lines of independent evidence which show that cell surface GalTase facilitates invasion and metastasis. ^

Neutrophil expression of ICAM1, CXCR1, and VEGFR1 in patients with breast cancer before and after adjuvant chemotherapy

BACKGROUND Distinct populations of neutrophils have been identified based on the expression of intercellular adhesion molecule 1 (ICAM1, CD54) and chemokine receptor 1 (CXCR1, interleukin 8 receptor α). AIM We analyzed the expression of vascular endothelial growth factor receptor 1 (VEGFR1), a physiological negative regulator of angiogenesis, on distinct populations of neutrophils from the blood of patients before and after adjuvant chemotherapy for breast cancer. MATERIALS AND METHODS Neutrophil populations were distinguished as reverse transmigrated (ICAM1(high)/CXCR1(low)), naïve (ICAM1(low)/CXCR1(high)), or tissue-resident neutrophils (ICAM1(low)/CXCR1(low)), and their VEGFR1 expression quantified. RESULTS Reverse transmigrated ICAM1(high)/CXCR1(low) neutrophilic granulocytes decreased significantly after chemotherapy and these were also the cells with highest mean fluorescence intensity for VEGFR1. CONCLUSION Chemotherapy mainly reduces the number of reverse transmigrated long-lived ICAM1(high)/CXCR1(low) VEGFR1-expressing neutrophils. The decrease of antiangiogenic VEGFR1 may have a potential impact on tumour angiogenesis in patients undergoing adjuvant chemotherapy.

Materno-fetal nutrient transfer across primary human trophoblast layer.

MATERNO-FETAL NUTRIENT TRANSFER ACROSS PRIMARY HUMAN TROPHOBLAST MONOLAYER Objectives: Polarized trophoblasts represent the transport and metabolic barrier between the maternal and fetal circulation. Currently human placental nutrient transfer in vitro is mainly investigated unidirectionallyon cultured primary trophoblasts, or bidirectionally on the Transwell® system using BeWo cells treated with forskolin. As forskolin can induce various gene alterations (e.g. cAMP response element genes), we aimed to establish a physiological primary trophoblast model for materno-fetal nutrient exchange studies without forskolin application. Methods: Human term cytotrophoblasts were isolated by enzymatic digestion and Percoll® gradient separation. The purity of the primary cells was assessed by flow cytometry using the trophoblast-specific marker cytokeratin-7. After screening different coating matrices, we optimized the growth conditions for the primary cytotrophoblasts on Transwell/ inserts. The morphology of 5 days cultured trophoblasts was determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Membrane makers were visualized using confocal microscopy. Additionally transport studies were performed on the polarized trophoblasts in the Transwell® system. Results: During 5 days culture, the trophoblasts (>90% purity) developed a modest trans-epithelial electrical resistance (TEER) and a sizedependent apparent permeability coefficient (Papp) to fluorescently labeled compounds (MW ~400-70’000D). SEM analyses confirmed a confluent trophoblast layer with numerous microvilli at day six, and TEM revealed a monolayer with tight junctions. Immunocytochemistry on the confluent trophoblasts showed positivity for the cell-cell adhesion molecule E-cadherin, the tight junction protein ZO-1, and the membrane proteins ABCA1 and Na+/K+-ATPase. Vectorial glucose and cholesterol transport studies confirmed functionality of the cultured trophoblast barrier. Conclusion: Evidence from cell morphology, biophysical parameters and cell marker expressions indicate the successful and reproducible establishment of a primary trophoblast monolayer model suitable for transport studies. Application of this model to pathological trophoblasts will help to better understand the mechanism underlying gestational diseases, and to define the consequences of placental pathology on materno-fetal nutrient transport.

Melanoma Cell-Intrinsic PD-1 Receptor Functions Promote Tumor Growth.

Therapeutic antibodies targeting programmed cell death 1 (PD-1) activate tumor-specific immunity and have shown remarkable efficacy in the treatment of melanoma. Yet, little is known about tumor cell-intrinsic PD-1 pathway effects. Here, we show that murine and human melanomas contain PD-1-expressing cancer subpopulations and demonstrate that melanoma cell-intrinsic PD-1 promotes tumorigenesis, even in mice lacking adaptive immunity. PD-1 inhibition on melanoma cells by RNAi, blocking antibodies, or mutagenesis of melanoma-PD-1 signaling motifs suppresses tumor growth in immunocompetent, immunocompromised, and PD-1-deficient tumor graft recipient mice. Conversely, melanoma-specific PD-1 overexpression enhances tumorigenicity, as does engagement of melanoma-PD-1 by its ligand, PD-L1, whereas melanoma-PD-L1 inhibition or knockout of host-PD-L1 attenuate growth of PD-1-positive melanomas. Mechanistically, the melanoma-PD-1 receptor modulates downstream effectors of mTOR signaling. Our results identify melanoma cell-intrinsic functions of the PD-1:PD-L1 axis in tumor growth and suggest that blocking melanoma-PD-1 might contribute to the striking clinical efficacy of anti-PD-1 therapy.

ICAM1 depletion reduces spinal metastasis formation in vivo and improves neurological outcome

INTRODUCTION Clinical treatment of spinal metastasis is gaining in complexity while the underlying biology remains unknown. Insufficient biological understanding is due to a lack of suitable experimental animal models. Intercellular adhesion molecule-1 (ICAM1) has been implicated in metastasis formation. Its role in spinal metastasis remains unclear. It was the aim to generate a reliable spinal metastasis model in mice and to investigate metastasis formation under ICAM1 depletion. MATERIAL AND METHODS B16 melanoma cells were infected with a lentivirus containing firefly luciferase (B16-luc). Stable cell clones (B16-luc) were injected retrogradely into the distal aortic arch. Spinal metastasis formation was monitored using in vivo bioluminescence imaging/MRI. Neurological deficits were monitored daily. In vivo selected, metastasized tumor cells were isolated (mB16-luc) and reinjected intraarterially. mB16-luc cells were injected intraarterially in ICAM1 KO mice. Metastasis distribution was analyzed using organ-specific fluorescence analysis. RESULTS Intraarterial injection of B16-luc and metastatic mB16-luc reliably induced spinal metastasis formation with neurological deficits (B16-luc:26.5, mB16-luc:21 days, p<0.05). In vivo selection increased the metastatic aggressiveness and led to a bone specific homing phenotype. Thus, mB16-luc cells demonstrated higher number (B16-luc: 1.2±0.447, mB16-luc:3.2±1.643) and increased total metastasis volume (B16-luc:2.87±2.453 mm3, mB16-luc:11.19±3.898 mm3, p<0.05) in the spine. ICAM1 depletion leads to a significantly reduced number of spinal metastasis (mB16-luc:1.2±0.84) with improved neurological outcome (29 days). General metastatic burden was significantly reduced under ICAM1 depletion (control: 3.47×10(7)±1.66×10(7); ICAM-1-/-: 5.20×10(4)±4.44×10(4), p<0.05 vs. control) CONCLUSION Applying a reliable animal model for spinal metastasis, ICAM1 depletion reduces spinal metastasis formation due to an organ-unspecific reduction of metastasis development.

Inflammatory markers in pediatric stroke: An attempt to better understanding the pathophysiology

BACKGROUND The mechanisms of childhood and perinatal arterial ischemic stroke (AIS) are poorly understood. Multiple risk factors include cerebral arteriopathy, congenital cardiac disease, infection, sickle cell disease, and maternal-fetal conditions in neonates. For infections and parainfectious conditions being the most important a possible inflammatory pathophysiology has long been suspected. This pilot study aims to detect, whether there are any abnormalities of inflammatory markers associated with childhood and neonatal stroke. METHODS The concentration of 23 different metalloproteinases (MMPs), tissue inhibitors of MMPs (TIMPs), endothelial factors, vascular cell adhesion proteins, and cytokines in plasma were measured in 12 children with AIS, 7 healthy age matched controls and 6 full term neonates with perinatal AIS. RESULTS At the time of the acute event children with AIS had significantly elevated levels of MMP-9, TIMP4, IL-6, IL-8 and CRP compared to controls (p < 0.05). Except for lower IL-6 and CRP levels the pattern of children with a history of varizella-zoster virus (VZV) and other viral infections did not differ to the non-infectious group. Median levels of MMP-1, MMP-2, TIMP-1, TIMP-2, sE-selectin, sICAM-1, sVCAM-1, IL-8, IL-10, TNF-alpha, VEGF, Fetuin A were found to be higher in the neonatal group when compared with older children. CONCLUSION This pilot study supports the assumption of an inflammatory process and up-regulation of metalloproteinases and their inhibitors, and altered pattern of circulating pro-inflammatory cytokines, CRP and vWF levels in pediatric and neonatal AIS. It highlights the feasibility but also difficulties for similar larger future studies that should aim to clarify childhood stroke etiopathogenesis and consecutive further therapeutic options.