The potential of adipokines in identifying multiple trauma patients at risk of developing multiple organ dysfunction syndrome.

BACKGROUND: Multiple organ dysfunction syndrome (MODS) and the consecutive multiple organ failure (MOF) are severe and dreaded complications with a high mortality in multiple trauma patients. The aim of this study was to investigate the potential of the adipokines leptin, resistin, interleukin-17A and interleukin-33 as possible biomarkers in the early posttraumatic inflammatory response and for identifying severely traumatized patients at risk of developing MODS. METHODS: In total, 14 multiple trauma patients with an injury severity score (ISS) ≥ 16 as well as a control group of 14 non-multiple trauma patients were included in this study and blood samples were taken at the time points 0, 6, 24, 48 and 72 h after admission. For the trauma patients, the SIRS and Denver MOF score were determined daily. The quantitative measurement of the plasma concentrations of the adipokines was performed using ELISA. RESULTS: In the statistical analysis, the multiple trauma patients showed statistically significant higher plasma concentrations of leptin, resistin, IL-17A and IL-33 compared to the control group. In addition, there was a statistically significant positive correlation between the concentrations of resistin, IL-17A and IL-33 and the corresponding SIRS scores and between the concentrations of resistin, IL-17A and IL-33 and the corresponding Denver MOF scores. Finally, ROC curve analysis revealed that the adipokines leptin and IL-17A are suitable diagnostic markers for the discrimination between multiple trauma patients with and without MOF. CONCLUSIONS: Leptin and IL-17A could be suitable diagnostic markers to identify severely injured patients with a developing SIRS and MOF earlier, to adjust surgical therapy planning and intensive care.

Direct comparison of 3D and 2D cultivation reveals higher osteogenic capacity of elderly osteoblasts in 3D.

BACKGROUND: The aim of this study was the investigation of the osteogenic potential of human osteoblasts of advanced donor age in 2D and 3D culture. METHODS: Osteoblasts were induced to osteogenic differentiation and cultivated, using the same polystyrene material in 2D and 3D culture for 2 weeks. Samples were taken to evaluate alkaline phosphatase (ALP) activity, mineralization and gene expression. RESULTS: Osteoprotegerin (OPG) levels were significantly increased (8.2-fold) on day 7 in 3D compared to day 0 (p < 0.0001) and 11.6-fold higher in 3D than in 2D (p < 0.0001). Both culture systems showed reduced osteocalcin (OC) levels (2D 85% and 3D 50% of basic value). Collagen type 1 (Col1) expression was elevated in 3D on day 7 (1.4-fold; p = 0.009). Osteopontin (OP) expression showed 6.5-fold higher levels on day 7 (p = 0.002) in 3D than in 2D. Mineralization was significantly higher in 3D on day 14 (p = 0.0002). CONCLUSION: Advanced donor age human primary osteoblasts reveal significantly higher gene expression levels of OPG, Col1 and OP in 3D than in monolayer. Therefore, it seems that a relatively high potential of bone formation in a natural 3D arrangement is presumably still present in osteoblasts of elderly people. TRIAL REGISTRATION: 5217/11 on the 22nd of Dec. 2011.

Author Correction: Effect of donor age and 3D-cultivation on osteogenic differentiation capacity of adipose-derived mesenchymal stem cells.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Effect of donor age and 3D-cultivation on osteogenic differentiation capacity of adipose-derived mesenchymal stem cells.

BACKGROUND AND PURPOSE: Age and co-morbidities compromise healing tendencies of traumatic fractures in geriatric patients. Non-healing fractures may need regenerative medicine techniques involving autologous mesenchymal stem cells (MSCs). Donor age may affect the viability and differentiation capacity of MSCs. We investigated age-related differences in adipose-derived MSCs (AMSCs) concerning osteogenic potential in 2D and 3D cultivation. MATERIALS AND METHODS: AMSCs were harvested from young (mean age: 37.5 ± 8.6 years) and old (mean age: 75.8 ± 9.2 years) patients. Cells were induced to osteogenic differentiation and cultivated in 2D and 3D for 14 days. Alkaline phosphatase (ALP) activity, mineralization and gene expression were investigated. RESULTS: ALP activity revealed highest levels in 3D of old AMSCs after 14 days. ALP expression showed significant rises in old vs. young cells in 2D (p = 0.0024). Osteoprotegerin revealed the highest levels in old AMSCs in 2D. Highest osteocalcin levels presented in young cells compared to old cells in 2D (p = 0.0258) and young cells in 3D (p = 0.0014). CONCLUSION: 3D arrangement of old AMSCs without growth factors is not ensuring superior osteogenesis in vitro. AMSCs, especially cells from older patients, reveal higher osteogenic potential in 2D than in 3D. 3D arrangement favors osteogenic potential of young cells.

Cytokine and immune cell profiling in the cerebrospinal fluid of patients with neuro-inflammatory diseases.

BACKGROUND: Cytokines play multiple roles during neuro-inflammatory processes and several cytokines have been studied in the context of specific diseases. This study provides a comprehensive picture of cerebrospinal fluid (CSF) changes during neuro-inflammation by analyzing multiple cytokines in combination with immune cell subsets and standard CSF parameters. METHODS: Using multiplex assays, we simultaneously measured 36 cytokines (CCL1-3, CCL7, CCL8, CCL11, CCL13, CCL19, CCL20, CCL22-27, CXCL1, CXCL2, CXCL5, CXCL6, CXCL8, CXCL9, CXCL11-13, CXCL16, CX3CL1, IL2, IL4, IL6, IL10, IL16, GM-CSF, IFNγ, MIF, TNFα, and MIB1ß) in the CSF and serum of 75 subjects. Diagnoses included clinically isolated syndrome and relapsing-remitting multiple sclerosis (MS, n = 18), secondary progressive MS (n = 8), neuro-syphilis (n = 6), Lyme neuro-borreliosis (n = 13), bacterial and viral meningitis (n = 20), and patients with non-inflammatory neurological diseases (NIND, n = 10). Cytokine concentrations were correlated with CSF standard parameters and CSF immune cell subsets (CD4 and CD8 T cells, B cells, plasmablasts, monocytes, and NK cells) quantified by flow cytometry. RESULTS: We observed increased levels of multiple cytokines (26/36) in patients with neuro-inflammatory diseases when compared to NIND that consistently correlated with CSF cell count and QAlbumin. Most CSF cytokine concentrations correlated with each other, but correlations between CSF and serum values were scarce (3/36). Within the CSF compartment, CXCL13 showed a strong association with B cells when analyzing all patients, as well as patients with an intact blood-brain barrier (BBB). NK cells positively correlated with CSF concentrations of multiple cytokines (22/36) when analyzing all patients. These correlations were maintained when looking at patients with a disrupted BBB but not detectable in patients with an intact BBB. CONCLUSIONS: Under conditions of neuro-inflammation, multiple CSF cytokines are regulated in parallel and most likely produced locally. A combined increase of CSF CXCL13 levels and B cells occurs under conditions of an intact BBB. Under conditions of a disrupted BBB, CSF NK cells show significantly increased values and seem to have a major contribution to overall inflammatory processes, reflected by a strong correlation with multiple cytokines. Future studies are necessary to address the exact kinetics of these cytokines during neuro-inflammation and their relation to specific diseases phenotypes.

Impact of Periprosthetic Fibroblast-Like Cells on Osteoclastogenesis in Co-Culture with Peripheral Blood Mononuclear Cells Varies Depending on Culture System.

Co-culture studies investigating the role of periprosthetic fibroblasts (PPFs) in inflammatory osteoclastogenesis reveal contrary results, partly showing an osteoprotective function of fibroblasts and high OPG expression in monolayer. These data disagree with molecular analyses of original periosteolytic tissues. In order to find a more reliable model, PPFs were co-cultivated with peripheral blood mononuclear cells (PBMCs) in a transwell system and compared to conventional monolayer cultures. The gene expression of key regulators of osteoclastogenesis (macrophage colony-stimulating factor (MCSF), receptor activator of NF-κB ligand (RANK-L), osteoprotegerin (OPG), and tumor necrosis factor alpha (TNFα)) as well as the ability of bone resorption were analyzed. In monolayer co-cultures, PPFs executed an osteoprotective function with high OPG-expression, low RANK-L/OPG ratios, and a resulting inhibition of osteolysis even in the presence of MCSF and RANK-L. For transwell co-cultures, profound changes in gene expression, with a more than hundredfold decrease of OPG and a significant upregulation of TNFα were observed. In conclusion, we were able to show that a change of culture conditions towards a transwell system resulted in a considerably more osteoclastogenic gene expression profile, being closer to findings in original periosteolytic tissues. This study therefore presents an interesting approach for a more reliable in vitro model to examine the role of fibroblasts in periprosthetic osteoclastogenesis in the future.

Immobilization of Denosumab on Titanium Affects Osteoclastogenesis of Human Peripheral Blood Monocytes.

Immobilization of proteins has been examined to improve implant surfaces. In this study, titanium surfaces were modified with nanofunctionalized denosumab (cDMAB), a human monoclonal anti-RANKL IgG. Noncoding DNA oligonucleotides (ODN) served as linker molecules between titanium and DMAB. Binding and release experiments demonstrated a high binding capacity of cDMAB and continuous release. Human peripheral mononuclear blood cells (PBMCs) were cultured in the presence of RANKL/MCSF for 28 days and differentiated into osteoclasts. Adding soluble DMAB to the medium inhibited osteoclast differentiation. On nanofunctionalized titanium specimens, the osteoclast-specific TRAP5b protein was monitored and showed a significantly decreased amount on cDMAB-titanium in PBMCs + RANKL/MCSF. PBMCs on cDMAB-titanium also changed SEM cell morphology. In conclusion, the results indicate that cDMAB reduces osteoclast formation and has the potential to reduce osteoclastogenesis on titanium surfaces.

Osteogenic Effect and Cell Signaling Activation of Extremely Low-Frequency Pulsed Electromagnetic Fields in Adipose-Derived Mesenchymal Stromal Cells.

Extremely low-frequency pulsed electromagnetic field (ELF-PEMF) devices have been used in the clinic for the treatment of bone disorders over the past 30 years. However, the underlying mechanism of which ELF-PEMFs exert an effect on tissues at a cellular level is not well understood. Hence, in this study, we explored the potential of different ELF-PEMF signals in modulating human adipose-derived mesenchymal stromal cells' (hAMSC) osteogenic capability. The cell proliferation rate was assessed using carboxyfluorescein succinimidyl ester (CFSE) method. The osteogenesis potential of cells was determined by alkaline phosphatase (ALP) activity, Alizarin-Red S staining, and RT-qPCR. Finally, the intracellular signaling pathway of a selected ELF-PEMF signal was examined using the PathScan Intracellular Signaling Array. Among the tested ELF-PEMF signals, program 20 (26 Hz) showed activation of the Akt and MAPK/ERK signaling cascade and significant upregulations of collagen I, alkaline phosphatase, and osteocalcin when compared to nonstimulated cells. This study demonstrates the potential of certain ELF-PEMF signal parameters to induce osteogenic differentiation of hAMSC and provides important clues in terms of the molecular mechanisms for the stimulation of osteogenic effects by ELF-PEMF on hAMSC.

Co-Culture with Human Osteoblasts and Exposure to Extremely Low Frequency Pulsed Electromagnetic Fields Improve Osteogenic Differentiation of Human Adipose-Derived Mesenchymal Stem Cells.

Human adipose-derived mesenchymal stem cells (Ad-MSCs) have been proposed as suitable option for cell-based therapies to support bone regeneration. In the bone environment, Ad-MSCs will receive stimuli from resident cells that may favor their osteogenic differentiation. There is recent evidence that this process can be further improved by extremely low frequency pulsed electromagnetic fields (ELF-PEMFs). Thus, the project aimed at (i) investigating whether co-culture conditions of human osteoblasts (OBs) and Ad-MSCs have an impact on their proliferation and osteogenic differentiation; (ii) whether this effect can be further improved by repetitive exposure to two specific ELF-PEMFs (16 and 26 Hz); (iii) and the effect of these ELF-PEMFs on human osteoclasts (OCs). Osteogenic differentiation was improved by co-culturing OBs and Ad-MSCs when compared to the individual mono-cultures. An OB to Ad-MSC ratio of 3:1 had best effects on total protein content, alkaline phosphatase (AP) activity, and matrix mineralization. Osteogenic differentiation was further improved by both ELF-PEMFs investigated. Interestingly, only repetitive exposure to 26 Hz ELF-PEMF increased Trap5B activity in OCs. Considering this result, a treatment with gradually increasing frequency might be of interest, as the lower frequency (16 Hz) could enhance bone formation, while the higher frequency (26 Hz) could enhance bone remodeling.

Adipose-derived mesenchymal stem cells from liposuction and resected fat are feasible sources for regenerative medicine.

BACKGROUND: The use of mesenchymal stem cells (MSCs) in research and in regenerative medicine has progressed. Bone marrow as a source has drawbacks because of subsequent morbidities. An easily accessible and valuable source is adipose tissue. This type of tissue contains a high number of MSCs, and obtaining higher quantities of tissue is more feasible. Fat tissue can be harvested using different methods such as liposuction and resection. First, a detailed isolation protocol with complete characterization is described. This also includes highlighting problems and pitfalls. Furthermore, some comparisons of these different harvesting methods exist. However, the later characterization of the cells is conducted poorly in most cases. METHODS: We performed an in-depth characterization over five passages including an investigation of the effect of freezing and thawing. Characterization was performed using flow cytometry with CD markers, metabolic activity with Alamar Blue, growth potential in between passages, and cytoskeleton staining. RESULTS: Our results show that the cells isolated with distinct isolation methods (solid versus liposuction "liquid") have the same MSC potential. However, the percentage of cells positive for the markers CD73, CD90, and CD105 is initially quite low. The cells isolated from the liquid fat tissue grow faster at higher passages, and significantly more cells display MSC markers. CONCLUSION: In summary, we show a simple and efficient method to isolate adipose-derived mesenchymal stem cells from different preparations. Liposuctions and resection can be used, whereas liposuction has more growth potential at higher passages.

Platelets modulate the immune response following trauma by interaction with CD4+ T regulatory cells in a mouse model.

CD4+ T regulatory cells (Tregs) play a pivotal role in the anti-inflammatory immune response following trauma. The mechanisms of CD4+ Treg activation are mostly unknown. Here, we hypothesize that platelets regulate CD4+ Treg activation following trauma. In a murine burn injury model (male C57Bl/6N mice), depletion of platelets or CD4+ Tregs was conducted. Draining lymph nodes, blood and spleen were harvested 2 h and 7 days after trauma. CD4+ Treg activation was measured using phospho- and conventional flow cytometry. Platelet activation was analyzed using thromboelastometry and flow cytometry. Trauma differentially activates CD4+ T cells, early after trauma only CD4+ Tregs are activated. Following burn injury, platelets augment the activation of CD4+ Tregs. This effect could only be seen early after trauma. While CD4+ Tregs influence hemostasis early following trauma, platelet activation markers were unchanged. Beyond their role in hemostasis, platelets are able to modulate the immunologic host response to trauma-induced injury by augmenting the activation of CD4+ Tregs. CD4+ Treg activation following trauma is considered protective. In addition, CD4+ Tregs are capable of modulating the hemostatic function of platelets. For the first time, we could show reciprocal activation of platelets and CD4+ Tregs as part of the protective immune response following trauma.

Presence of starch enhances in vitro biodegradation and biocompatibility of a gentamicin delivery formulation.

The effect of α-amylase degradation on the release of gentamicin from starch-conjugated chitosan microparticles was investigated up to 60 days. Scanning electron microscopic observations showed an increase in the porosity and surface roughness of the microparticles as well as reduced diameters. This was confirmed by 67% weight loss of the microparticles in the presence of α-amylase. Over time, a highly porous matrix was obtained leading to increased permeability and increased water uptake with possible diffusion of gentamicin. Indeed, a faster release of gentamicin was observed with α-amylase. Starch-conjugated chitosan particles are non-toxic and highly biocompatible for an osteoblast (SaOs-2) and fibroblast (L929) cell line as well as adipose-derived stem cells. When differently produced starch-conjugated chitosan particles were tested, their cytotoxic effect on SaOs-2 cells was found to be dependent on the crosslinking agent and on the amount of starch used.

Pantoprazole decreases cell viability and function of human osteoclasts in vitro.

Proton pump inhibitors (PPIs) are commonly prescribed drugs that decrease stomach acidity and are thus often used to treat gastroesophageal reflux disease and as a preventative agent for the adverse effects of nonsteroidal anti-inflammatory drugs on the stomach mucosa. In recently published literature, an association between proton pump inhibitor administration and increased fracture risk has been stated. In order to reveal the underlying pathomechanisms of these observations, the effects of pantoprazole, a representative of the proton pump inhibitors, on human osteoclasts in vitro were evaluated in this study. Osteoclasts were stimulated with increasing concentrations of pantoprazole ranging from 0 µg/mL to 10 µg/mL over a period of seven days. Cell viability and tartrate-resistant acid phosphatase (TRAP) activity assays were performed after 1 day, 3 days, and 7 days, respectively. Here, stimulated osteoclasts presented a significantly lower viability and TRAP activity than the negative controls. Osteoclast-specific gene expression was evaluated after seven days and revealed no significant differences between all samples. Overall, the bone degrading and resorptive function of osteoclasts is inhibited by the administration of proton pump inhibitors. While PPI-related fractures through "basic multicellular unit" dysfunction are unlikely, the underlying pathomechanism remains unknown.

Pantoprazole increases cell viability and function of primary human osteoblasts in vitro.

Proton pump inhibitors (PPIs) are a class of drugs that irreversibly inhibit the H(+)/K(+)-ATPase in gastric parietal cells. Since an association between PPI use and increased fracture risk has been found, the aim of this study was to detect potential adverse effects of pantoprazole, a representative of the PPIs, on primary human osteoblasts in vitro. The isolated cells were stimulated with pantoprazole concentrations ranging from 0 µg/ml to 10 µg/ml. Changes in proliferation, total cell number, viability, cytotoxicity, alkaline phosphatase activity, total protein synthesis and gene expression on mRNA level were determined over a period of 7 days. Pantoprazole stimulation resulted in increased viability and decreased cytotoxicity in the osteoblasts. The proliferation rate was stable and so was the relative cell number. Only at the highest pantoprazole concentration on day 7, a slight decrease of the cell number was detected. Alkaline phosphatase activity increased over the tested period under exposure to pantoprazole (p < 0.05 at 3 µg/ml and 10 µg/ml pantoprazole). Osteoblast-specific gene expression was increased through pantoprazole stimulation compared to the control on day 3. Towards day 7, gene expression returned to baseline levels or decreased slightly compared to unexposed cells. Interestingly, this in vitro experiment detected no evidence of adverse effects of PPIs on primary human osteoblasts. Osteoblasts were rather more viable with increased mitochondrial activity, gene expression and protein synthesis under pantoprazole stimulation. Therefore, these in vitro results do not suggest that impaired osteoblast function is the cause of an increased fracture risk in patients under PPI therapy.