Sex differences in the percentage of IRF5 positive B cells are associated with higher production of TNF-α in women in response to TLR9 in humans.

BACKGROUND: The clinical course and outcome of many diseases differ between women and men, with women experiencing a higher prevalence and more severe pathogenesis of autoimmune diseases. The precise mechanisms underlying these sex differences still remain to be fully understood. IRF5 is a master transcription factor that regulates TLR/MyD88-mediated responses to pathogen-associated molecular patterns (PAMPS) in DCs and B cells. B cells are central effector cells involved in autoimmune diseases via the production of antibodies and pro-inflammatory cytokines as well as mediating T cell help. Dysregulation of IRF5 expression has been reported in autoimmune diseases, including systemic lupus erythematosus, primary Sjögren syndrome, and rheumatoid arthritis. METHODS: In the current study, we analyzed whether the percentage of IRF5 positive B cells differs between women and men and assessed the resulting consequences for the production of inflammatory cytokines after TLR7- or TLR9 stimulation. RESULTS: The percentage of IRF5 positive B cells was significantly higher in B cells of women compared to men in both unstimulated and TLR7- or TLR9-stimulated B cells. B cells of women produced higher levels of TNF-α in response to TLR9 stimulation. CONCLUSIONS: Taken together, our data contribute to the understanding of sex differences in immune responses and may identify IRF5 as a potential therapeutic target to reduce harmful B cell-mediated immune responses in women.

Reduction of Potentially Inappropriate Medication in the Elderly.

BACKGROUND: Medications with an unfavorable risk-benefit profile in the elderly, and for which there are safer alternatives, are designated as potentially inappropriate medications (PIM). The RIME trial (Reduction of Potentially Inappropriate Medication in the Elderly) was based on PRISCUS, a list of PIM that was developed in 2010 for the German pharmaceuticals market. In this trial, it was studied whether special training and the PRISCUS card could lessen PIM and undesired drug-drug interactions (DDI) among elderly patients in primary care. METHODS: A three-armed, cluster-randomized, controlled trial was carried out in two regions of Germany. 137 primary care practices were randomized in equal numbers to one of two intervention groups-in which either the primary care physicians alone or the entire practice team received special training-or to a control group with general instructions about medication. The primary endpoint was the percentage of patients with at least one PIM or DDI (PIM/DDI) per practice. The primary hypothesis was that at 1 year this endpoint would be more effectively lowered in the intervention groups compared to the control group. RESULTS: Among 1138 patients regularly taking more than five drugs, 453 (39.8%) had at least one PIM/DDI at the beginning of the trial. The percent - ages of PIM/DDI at the beginning of the trial and 1 year later were 43.0% and 41.3% in the intervention groups and 37.0% and 37.6% in the control group. The estimated intervention effect of any intervention (69 practices) versus control (68 practices) was 2.3% (p = 0.36), while that of team training (35 practices) versus physician training (34 practices) was 4.3% (p = 0.22). CONCLUSION: The interventions in the RIME trial did not significantly lower the percentage of patients with PIM or DDI.

Innate immune responses to toll-like receptor stimulation are altered during the course of pregnancy.

During pregnancy the maternal immune system has to develop tolerance towards the developing fetus. These changes in maternal immunity can result in increased severity of certain infections, but also in amelioration of autoimmune diseases. Pregnancy-related hormones have been suggested to play a central role in the adaptation of the maternal immune system, but their specific effects on innate immune function is not well understood. In a longitudinal study of pregnant women, we investigated innate immune cell function in response to toll-like receptors (TLR) 4 and 7 stimulation, two TLR pathways playing a critical role in early innate immune recognition of bacteria and viruses. IFNα production by TLR7-stimulated pDCs was decreased in early pregnancy, and increased towards the end of pregnancy. In contrast, pro-inflammatory TLR4-induced TNFα production by monocytes was increased during early pregnancy, but declined after the first trimester. Changes in cytokine production were associated with changes in pregnancy-related hormones and monocyte subpopulations over the course of pregnancy. These data demonstrating a significant association between pregnancy-related hormones and modulation of innate immune responses mediated by TLRs provide novel insights into the immunological adaptations occurring during pregnancy.

"It's MAGIC"--development of a manageable geriatric assessment for general practice use.

BACKGROUND: Geriatric assessments are established tools in institutional care since they enable standardized detection of relevant age-related disorders. Geriatric assessments could also be helpful in general practice. However, they are infrequently used in this setting, mainly due to their lengthy administration. The aim of the study was the development of a "manageable geriatric assessment--MAGIC", specially tailored to the requirements of daily primary care. METHODS: MAGIC was developed based on the comprehensive Standardized Assessment for Elderly People in Primary Care (STEP), using four different methodological approaches: We relied on A) the results of the PRISCUS study by assessing the prevalence of health problems uncovered by STEP, the importance of the respective problems rated by patients and general practitioners, as well as the treatment procedures initiated subsequently to the assessment. Moreover, we included findings of B) a literature analysis C) a review of the STEP assessment by experienced general practitioners and D) focus groups with general practitioners. RESULTS: The newly created MAGIC assessment consists of 9 items and covers typical geriatric health problems and syndromes: function, falls, incontinence, cognitive impairment, impaired ears and eyes, vaccine coverage, emotional instability and isolation. CONCLUSIONS: MAGIC promises to be a helpful screening instrument in primary care consultations involving elderly multimorbid patients. Applicable within a minimum of time it still covers health problems highly relevant with regard to a potential loss of autonomy. Feasibility will be tested in the context of a large, still ongoing randomized controlled trial on "reduction of potentially inadequate medication in elderly patients" (RIME study; DRKS-ID: DRKS00003610) in general practice.

Androstenediol exerts salutary effects on chemokine response after trauma-hemorrhage and sepsis in mice.

OBJECTIVES: The pathogenesis of multiple organ dysfunction syndrome and sepsis after polytrauma is related to the posttraumatic immune response and the associated release of inflammatory mediators. There exists a gender dimorphism in the posttraumatic host response. Sex steroids are believed to beneficially modulate the posttraumatic immune response. The specific effect of androstenediol on chemokines after trauma is unknown. We investigated whether the application of androstenediol has an effect on plasma chemokine levels and the associated remote organ damage in a two-hit mouse-model of trauma-hemorrhage, cecal ligation, and cecal puncture. MATERIALS AND METHODS: Traumatic hemorrhage was induced followed by androstenediol application and volume resuscitation. Thereafter, androstenediol was given once daily in combination with a vehicle (Intralipid). The control group was injected with a solution containing only the vehicle at the same time points as the treatment groups' androstenediol applications. Sepsis was induced by cecal ligation and cecal puncture 48 hours afterward. Four hours after cecal ligation and cecal puncture, plasma measurements of chemokines were performed. Pulmonary infiltration by polymorphonuclear lymphocytes was measured by immunhistochemical staining and myeloperoxidase measurements were taken. RESULTS: Application of androstenediol led to significantly decreased monocyte chemoattractant protein-1, monocyte chemoattractant protein-3, macrophage inflammatory protein-1α, and macrophage inflammatory protein-1ß levels compared with the control animals after trauma-hemorrhage, cecal ligation, and cecal puncture (P < 0.05). Pulmonary infiltration and myeloperoxidase activity were significantly decreased in androstenediol-treated animals (P < 0.05). CONCLUSION: Androstenediol modulates the immune response after trauma-hemorrhage, cecal ligation, and cecal puncture by reducing systemic chemokine levels, which are known to direct immune cells into the tissue possibly leading to organ damage. Androstenediol represents a potential therapeutic agent after major trauma in high-risk patients.

Protective effects of finasteride on the pulmonary immune response in a combined model of trauma-hemorrhage and polymicrobial sepsis in mice.

UNLABELLED: Literature supports findings about a gender specific outcome following multiple trauma. Male sex hormones such as dihydrotestosterone (DHT) exert deleterious effects on the posttraumatic immune response whereas increased estradiol concentrations are correlated with improved outcome. Pretreatment with the 5α-reductase inhibitor finasteride resulted in an improved outcome following trauma-hemorrhage (TH) in mice. The present study tested the hypothesis that finasteride exerts beneficial effects on the posttraumatic immune response also in a combined setting of TH and sepsis when administered during the resuscitation process. MATERIAL AND METHODS: Male C57BL/6N-mice were subjected to TH (blood pressure, 35 mm Hg, 60 min) followed by finasteride application and fluid resuscitation. Thereafter, finasteride was administered every 12h. 24h after TH, sepsis was induced by cecal ligation and puncture (CLP) or sham operation was performed. Plasma cytokines (MIP-1α, MIP-1ß, TNF-α, MCP-1, IL-6), productive capacity by alveolar macrophages (AM) and systemic estradiol levels were determined 4 h thereafter. The expression of pro-inflammatory mediators in lung tissue was evaluated by PCR. Pulmonary infiltration of PMN was determined by immunohistochemical staining. RESULTS: Finasteride treatment resulted in a reduced posttraumatic cytokine secretion of AM as well as in a decreased concentration of MCP-1 and MIP-1ß in lung tissue. Systemic estradiol levels were increased following finasteride treatment. CONCLUSION: Finasteride mediates salutary effects on the pulmonary immune response using a therapeutical approach following TH-CLP in mice. Thus, finasteride might represent a relevant therapeutic substance following major trauma also in the clinical setting.

Selective blockade of interleukin-6 trans-signaling improves survival in a murine polymicrobial sepsis model.

OBJECTIVE: The pleiotropic cytokine interleukin (IL)-6 seems to play a pivotal role in sepsis, but contradictory findings in animal models impede a rationale for therapies directed against IL-6. IL-6 signals by two mechanisms via the ubiquitous transmembrane glycoprotein 130 (gp130): "classic" signaling using membrane-bound IL-6 receptor (IL-6R) and trans-signaling using soluble IL-6R (sIL-6R). Trans-signaling is selectively inhibited by soluble gp130 (sgp130). The aim of this study was to systematically compare complete blockade of IL-6 signaling (using a neutralizing anti-IL-6 antibody) and selective blockade of IL-6 trans-signaling (using a fusion protein of sgp130 and the crystallizable fragment of immunoglobulin G1, sgp130Fc) in a standardized cecal ligation and puncture (CLP) sepsis model. DESIGN: Animal study. SETTING: Animal laboratory. SUBJECTS: C57BL/6J mice. INTERVENTIONS: We performed a 96-hr dose-response study and a 24-hr study to investigate short-term mechanisms. In the 96-hr study, CLP was performed in 120 randomized mice (20 mice received vehicle, 10 mice per dose group). Mice were treated with equimolar doses of sgp130Fc (0.01/0.1/1/10 mg/kg) or anti-IL-6 (0.008/0.08/0.8/8 mg/kg) 24 hrs before CLP. Two additional groups received 0.5 mg/kg sgp130Fc 24 hrs before or 1 mg/kg sgp130Fc 24 hrs after CLP. Survival and activity scores were obtained daily until 96 hrs after CLP. In the 24-hr study, mice were randomized into four groups with 10 animals each (sham/vehicle, CLP/vehicle, CLP/anti-IL-6 [0.8 mg/kg], and CLP/sgp130Fc [1 mg/kg]) and killed after 24 hrs. MEASUREMENTS AND MAIN RESULTS: In contrast to anti-IL-6, pretreatment with sgp130Fc significantly and dose-dependently increased survival from 45% to 100%. In addition, 1 mg/kg sgp130Fc administered 24 hrs after CLP increased survival from 45% to 80%. Mechanistically, sgp130Fc efficacy was reflected by complete prevention of epithelial cell apoptosis in the jejunum after CLP, which was not achieved with anti-IL-6. CONCLUSION: Selective inhibition of IL-6 trans-signaling by sgp130Fc has considerable potential for the treatment of sepsis and related disorders.

TLR4 influences the humoral and cellular immune response during polymicrobial sepsis.

As part of the innate immune system, Toll-like receptors (TLRs) react rapidly on a pathogen challenge without prior exposure. Although it is well known that TLR4 is associated with the receptor for lipopolysaccharide (LPS), its role during sepsis has not yet been clearly defined. To study this,polymicrobial sepsis was induced in male C3H/HeN (TLR4 wild type) and C3H/HeJ (TLR4 mutant) mice by caecal ligation and puncture (CLP).A total of 48 h following the surgical procedure, the mice were sacrificed and plasma was collected.Kupffer cells were isolated and ex vivo cytokine production and plasma levels were determined. Lung neutrophil influx was investigated by myeloperoxidase (MPO) content and immunohistochemistry. T-cell subtypes in blood and spleen were determined by flow cytometry.Mice with intact TLR4 (wild type) had increased Kupffer cell IL-6 production and increased plasma levels as compared with C3H/HeJ mice following sepsis. Furthermore, wild type mice showed increased neutrophil influx in lungs and lower percentages of CD8+ splenocytes. This was accompanied with less activity, increased weight loss and decreased core temperature.We conclude that TLR4 influences the humoral and cellular response during the course of sepsis and lack of TLR4 reduces markers of the systemic inflammatory response as well as distant organ damage.Therefore, TLR4 could act as a future therapeutic target modulating the immune response during sepsis.

Activity of lymphocyte subpopulations in polymicrobial sepsis and DHEA treatment in IL-6 knockout mice.

INTRODUCTION: Sepsis with subsequent multiorgan dysfunction remains the leading cause of mortality in trauma patients. A gender dimorphism in the host response after trauma and sepsis has been revealed. Dehydroepiandrosterone (DHEA), one of the most abundant adrenal sexual steroid hormones, seems to have a protective immunological effect in sepsis. Knowledge of the pathway is sparse; however, a cellular modulation mediated by interleukin-6 (IL-6) has been proposed. MATERIALS AND METHODS: The effect of DHEA on survival, clinical parameters and the cellular immune system (T lymphocytes and NK cells) was examined in a model of polymicrobial sepsis induced by cecal ligation and puncture. For clarification of the role of IL-6 in the protective effect of DHEA, we used IL-6 knockout mice (IL-6(-/-)). As controls, experiments were performed on wild-type mice (WT). RESULTS: The administration of DHEA in IL-6(-/-) mice did not affect mortality, as it was not significantly different from WT mice without DHEA application. The cellular immune response was influenced, as seen by a significant reduction in the percentage of CD8+ and NK cells in WT animals. CONCLUSIONS: Mortality rates in IL-6(-/-) mouse strains were not lowered by DHEA; therefore, a limited effect of IL-6 on this pathway has to be proposed. NK cells may be one of the effector cells of the protective mechanisms of DHEA, whilst the role of CD8+ lymphocytes remains unclear. Consequently, DHEA might be presented as a possible adjuvant therapy after septic insult for modulation of the dysregulated immune system.

Macrophage-activating lipopeptide-2 exerts protective effects in a murine sepsis model.

It is still a major problem to achieve successful therapy in polymicrobial sepsis. Stimulation of the innate immune system via Toll-like receptors (TLRs) 2 and 6 had beneficial effects on chronic inflammatory disorders and a severe peritonitis model when administered 4 days before induction. In the present study, the hypothesis whether the TLR-2 and TLR-6 pathway can also be used as a therapeutic agent parallel to sepsis induction and several hours after the induction was tested. Therefore, the TLR-2 and TLR-6 agonist macrophage-activating lipopeptide 2 (MALP-2) was applied simultaneous to cecal ligation and puncture-sepsis induction and 6 h thereafter. Vehicle-treated animals served as controls. Survival, activity, cytokine levels at different time points, and pulmonary neutrophil infiltration were determined. Improved survival was found after both MALP-2 treatments in comparison with untreated controls. The treatment resulted in reduced monocyte chemotactic protein 1 levels in the plasma; furthermore, pulmonary infiltration by neutrophils was decreased. These results demonstrate a beneficial effect of MALP-2 as a therapeutic agent in polymicrobial sepsis in the cecal ligation and puncture mouse model.

DHEA-dependent and organ-specific regulation of TNF-alpha mRNA expression in a murine polymicrobial sepsis and trauma model.

INTRODUCTION: Dehydroepiandrosterone (DHEA) improves survival after trauma and sepsis, while mechanisms of action are not yet fully understood. Therefore, we investigated the influence of DHEA on local cytokine expression in a two-hit model. METHODS: Male NMRI mice were subjected to femur fracture/hemorrhagic shock and subsequent sepsis. Sham-operated animals were used as controls. DHEA (25 mg/kg) or vehicle was administered daily. Mortality rate, activity and body temperature were determined daily after sepsis induction. TNF-alpha, IL-1beta and IL-10 mRNA expression pattern were investigated in lung and liver tissue after 48 and 96 hours. RESULTS: DHEA treatment resulted in a significantly reduced mortality rate and improvements in the clinical status. On cytokine level, only TNF-alpha was significantly reduced in the cecal ligation and puncture (CLP)-vehicle group in both tissues after 48 hours. This suppression could be restored by DHEA administration. In contrast, after 96 hours, TNF-alpha was up-regulated in the CLP-vehicle group while remaining moderate by DHEA treatment in liver tissue. CONCLUSIONS: The improved outcome after DHEA treatment and trauma is coherent with restoration of TNF-alpha in liver and lung after 48 hours and a counter-regulatory attenuation of TNF-alpha in liver after 96 hours. Thus, DHEA seems to act, time and organ dependent, as a potent modulator of TNF-alpha expression.

Insulin therapy induces changes in the inflammatory response in a murine 2-hit model.

Post-traumatic complications commonly seen on intensive care units include sepsis and associated disorders, which are accompanied by alterations in inflammatory cytokine expression patterns and in activation of neutrophils. Hyperglycaemia, often occurring after trauma and sepsis, is a further risk factor for morbidity and mortality among critically ill people. Clinical investigations have suggested that strict glycaemic control by insulin titration reduces overall mortality. This study aimed to further elucidate the pathophysiological and immunomodulative actions of insulin. Femoral fracture was induced in a murine model, followed by 1h of haemorrhage. Two days after the first hit, sepsis was induced by caecal ligation and puncture (CLP). In control animals, laparotomy only was performed. Insulin in two different concentrations (10IU or 20IU) or vehicle was administered daily. Insulin therapy was associated with improvement of clinical parameters, slightly improved survival rates and, in lungs and liver, fewer infiltrating neutrophils and reduced IL-6 and IL-10 mRNA expression. These results suggested that, in this animal model, insulin had a direct anti-inflammatory effect that was independent of modulation of blood glucose levels.

Depletion of NK cells in a murine polytrauma model is associated with improved outcome and a modulation of the inflammatory response.

Sepsis and associated diseases such as systemic inflammatory response syndrome and multiple organ dysfunction syndrome represent common posttraumatic complications on intensive care units induced by a variety of body defense mechanisms. Natural killer (NK) cells are part of the innate immune system. They are thought to play an important role in the development of such syndromes by interplay with other immune cell types and subsequent activation of the inflammatory cascade. To test this hypothesis, NK cells were depleted by administration of antimouse asialo-GM1 antibody in a murine polytrauma model consisting of femur fracture, hemorrhagic shock, and subsequent sepsis. Mortality and immune parameters such as cytokine expression in lung and liver, lymphocyte phenotyping, lymphocyte apoptosis, and organ pathology were determined 96 h after sepsis induction. Survival values showed 50% in the control sepsis group and 100% after NK cell depletion. Thus, NK cell depletion resulted in 50% mortality reduction. Furthermore, we found reductions in the inflammatory response, represented by IL-6 expression in liver, and a decrease in infiltrating neutrophils in the liver and lung. In addition, lymphocyte apoptosis in spleen was decreased by depletion of NK cells. Taken together, these data demonstrate that NK cells contribute to the pathogenetic pathways in a murine polytrauma model. One main mechanism of action seems to be the induction of systemic inflammatory events. Thus, depletion of NK cells results in attenuated inflammation and an overall improvement in outcome. Therefore, NK cells can be considered as important targets for therapeutic strategies.

Tissue engineering of tendons and ligaments by human bone marrow stromal cells in a liquid fibrin matrix in immunodeficient rats: results of a histologic study.

INTRODUCTION: The original complex structure and mechanical properties are not fully restored after ligament and tendon injuries. Due to their high proliferation rate and differentiation potential, Bone Marrow Stromal Cells (BMSC) are considered to be an ideal cell source for tissue engineering to optimize the healing process. Ideal matrices for tissue engineering of ligaments and tendons should allow for homogenous cell seeding and offer sufficient stability. MATERIAL AND METHODS: A mixture of human BMSC and liquid fibrin glue was injected into a standardized full-thickness window defect of the patellar tendon of immunodeficient rats (BMSC group). The histology of the tissue was analysed 10 and 20 days postoperatively and compared to four control groups. These groups consisted of a cohort with a mixture of human fibroblasts and fibrin glue, fibrin glue without cells, a defect group without treatment, and a group with uninjured patellar tendon tissue. RESULTS: Tendon defects in the BMSC group revealed dense collagen fibres and spindle-shaped cells, which were mainly orientated along the loading axis. Histologic sections of the control groups, especially of untreated defects and of defects filled with fibrin glue only, showed irregular patterns of cell distribution, irregular formed cell nucleoli and less tissue maturation. Compared to healthy tendon tissue, higher numbers of cells and less intense matrix staining was observed in the BMSC group. No ectopic bone or cartilage formation was observed in any specimen. CONCLUSIONS: Injection of human BMSC in a fibrin glue matrix appears to lead to more mature tissue formation with more regular patterns of cell distribution. Advantages of this "in-vivo" tissue engineering approach are a homogenous cell-matrix mixture in a well-known and approved biological matrix, and simple, minimally-invasive application by injection.

Distinct involvement of p38-, ERK1/2 and PKC signaling pathways in C5a-mediated priming of oxidative burst in phagocytic cells.

C5a exerts various known harmful functions during experimental sepsis and blocking strategies demonstrated survival benefits in experimental sepsis. We investigated its potential for priming of oxidative burst in blood neutrophils and monocytes and the involvement of various signaling pathways. We here report that C5a induced priming of neutrophils and monocytes for Escherichia coli- and PMA-induced oxidative burst. This effect was strongly dependent on intact ERK1/2 signaling. P38 inhibition resulted in abrogation of C5a-induced priming only for E. coli-induced oxidative burst and PKC blockade had this effect only for PMA-induced burst. JNK inhibition had no impact. Our results demonstrate for the first time distinct involvement of ERK1/2, p38 and PKC pathways for C5a-induced priming of oxidative burst in phagocytes.

The phosphatidylinositol 3-kinase signaling pathway exerts protective effects during sepsis by controlling C5a-mediated activation of innate immune functions.

The PI3K/Akt signaling pathway has been recently suggested to have controversial functions in models of acute and chronic inflammation. Our group and others have reported previously that the complement split product C5a alters neutrophil innate immunity and cell signaling during the onset of sepsis and is involved in PI3K activation. We report in this study that in vivo inhibition of the PI3K pathway resulted in increased mortality in septic mice accompanied by strongly elevated serum levels of TNF-alpha, IL-6, MCP-1, and IL-10 during sepsis as well as decreased oxidative burst activity in blood phagocytes. PI3K inhibition in vitro resulted in significant increases in TLR-4-mediated generation of various proinflammatory cytokines in neutrophils, whereas the opposite effect was observed in PBMC. Oxidative burst and phagocytosis activity was significantly attenuated in both neutrophils and monocytes when PI3K activation was blocked. In addition, PI3K inhibition resulted in strongly elevated TLR-4-mediated generation of IL-1beta and IL-8 in neutrophils when these cells were co-stimulated with C5a. C5a-induced priming effects on neutrophil and monocyte oxidative burst activity as well as C5a-induced phagocytosis in neutrophils were strongly reduced when PI3K activation was blocked. Our data suggest that the PI3K/Akt signaling pathway controls various C5a-mediated effects on neutrophil and monocyte innate immunity and exerts an overall protective effect during experimental sepsis.

Nucleofection is the most efficient nonviral transfection method for neuronal stem cells derived from ventral mesencephali with no changes in cell composition or dopaminergic fate.

Neuronal progenitor cells (NPCs) play an important role in potential regenerative therapeutic strategies for neurodegenerative diseases, such as Parkinson disease. However, survival of transplanted cells is, as yet, limited, and the identification of grafted cells in situ remains difficult. The use of NPCs could be more effective with regard to a better survival and maturation when transfected with one or more neurotrophic factors. Therefore, we investigated the possibility of transfecting mesencephalic neuronal progenitors with different constructs carrying neurotrophic factors or the expression reporters enhanced green fluorescence protein (EGFP) and red fluorescent protein (DsRed). Different techniques for transfection were compared, and the highest transfection rate of up to 47% was achieved by nucleofection. Mesencephalic neuronal progenitors survived the transfection procedure; 6 hours after transfection, viability was approximately 40%, and the transfected cells differentiated into, for example, tyrosine hydroxylase-positive neurons. Within the group of transfected cells, many progenitors and several neurons were found. To provide the progenitor cells with a neurotrophic factor, different isoforms of fibroblast growth factor-2 were introduced. To follow the behavior of the transfected cells in vitro, functional tests such as the cell viability assay (water-soluble tetrazolium salt assay [WST-1]) and the cell proliferation assay (5-bromo-2'-deoxyuridine-enzyme-linked immunosorbent assay) were performed. In addition, these transfected NPCs were viable after transplantation, expressed tyrosine hydroxylase in vivo, and could easily be detected within the host striatum because of their EGFP expression. This study shows that genetic modification of neural progenitors could provide attractive perspectives for new therapeutic concepts in neurodegenerative diseases.

Dehydroepiandrosterone administration modulates endothelial and neutrophil adhesion molecule expression in vitro.

INTRODUCTION: The steroid hormone dehydroepiandrosterone (DHEA) exerts protecting effects in the treatment of traumatic and septic complications in several animal models. This effect goes along with reduced amounts of infiltrating immune cells in organs such as lung and liver. However, the underlying mechanisms of DHEA action are still not known. Adhesion molecules are important for the extravasation of neutrophils into organs where they may exhibit detrimental effects. Therefore, we investigated the in vitro effect of DHEA on the expression pattern of adhesion molecules of human endothelial cells and neutrophils. METHODS: Endothelial cells derived from human umbilical cord were subjected to an lipopolysaccharide (LPS) challenge. DHEA was administered in two different concentrations, 10(-5) M and 10(-8) M, as a single stimulus or in combination with LPS challenge. After two, four and 24 hours, fluorescence activated cell sorter (FACS) analysis for vascular cell adhesion molecule-1, intercellular adhesion molecule-1 and E-selectin was performed. Neutrophils were freshly isolated from blood of 10 male healthy volunteers, stimulated the same way as endothelial cells and analyzed for surface expression of L-selectin, CD11b and CD18. RESULTS: In the present study, we were able to demonstrate effects of DHEA on the expression of every adhesion molecule investigated. DHEA exhibits opposite effects to those seen upon LPS exposure. Furthermore, these effects are both time and concentration dependent as most DHEA specific effects could be detected in the physiological concentration of 10(-8) M. CONCLUSION: Thus, we conclude that one mechanism by which DHEA may exert its protection in animal models is via the differential regulation of adhesion molecule expression.

L-selectin: adhesion, signalling and its importance in pathologic posttraumatic endotoxemia and non-septic inflammation.

The leucocyte expressed surface-bound L-selectin belongs to the selectin family of adhesion molecules. It exhibits adhesive as well as signalling functions. Mainly, it is of importance in lymphocyte homing and in the extravasation of leucocytes into the surrounding tissue during inflammation. Acting in the initial step of the cell adhesion cascade, L-selectin is responsible for the rolling of leucocytes on endothelial layers. Therefore, L-selectin is thought to be an adequate target for pharmacological interventions. Beneath the discussion of the molecules' general features like molecule structure and its regulation, the review focuses firstly on L-selectin in the context of posttraumatic inflammatory disorders, and secondly on the importance of L-selectin specific signalling events.

Modulation of proliferation and differentiation of human bone marrow stromal cells by fibroblast growth factor 2: potential implications for tissue engineering of tendons and ligaments.

Bone marrow stromal cells (BMSCs) play a central role in the repair and regeneration of mesenchymal tissues. For tissue engineering of ligaments and tendons, both stimulation of cell proliferation and differentiation with increased expression of essential extracellular matrix proteins and cytoskeletal elements are desirable. This study analyzes the effect of low-dose (3 ng/mL) fibroblast growth factor 2 (FGF-2) and high-dose FGF-2 (30 ng/mL) on proliferation (bromodeoxyuridine content, spectrophotometry), differentiation (transcription of collagen I, collagen III, fibronectin, elastin, alpha-smooth muscle actin, and vimentin, reverse transcription-polymerase chain reaction, and cell density and apoptosis (annexin V, fluorescence-activated cell sorting) of human BMSCs, and compares the results with those of a control group without FGF-2. Low-dose FGF-2 triggered a biphasic BMSC response: on day 7, cell proliferation reached its maximum and was significantly higher compared with the other groups. On days 14 or 28, collagen I, collagen III, fibronectin, and alpha- smooth muscle actin mRNA expression was significantly enhanced in the presence of low-dose FGF-2. In contrast, high-dose FGF-2 did not stimulate differentiation or proliferation. Vimentin mRNA was expressed only in cultures with low-dose and high-dose FGF-2 after 14 and 28 days. Cell density was significantly higher in cultures with low-dose FGF-2 compared with the group with high-dose FGF-2 on days 7, 14, and 28. The apoptosis rate remained stable, at a rather high level, in all groups. Microscopic investigation of the cell cultures with low-dose FGF-2 showed more homogeneous, dense, fibroblast-like, spindle-shaped cells with long cell processes compared with cultures with high-dose, or no FGF-2. Low-dose FGF-2 may be useful for tissue engineering of ligaments and tendons by increasing BMSC proliferation and stimulating mRNA expression of specific extracellular matrix proteins and cytoskeletal elements.