Bromo-substituted indirubins for inhibition of protein kinase-mediated signalling involved in inflammatory mediator release in human monocytes.

Targeting protein kinases that regulate signalling pathways in inflammation is an effective pharmacological approach to alleviate uncontrolled inflammatory diseases. In this context, the natural product indirubin and its 6-bromo-substituted analogue 6-bromoindirubin-3 -glycerol-oxime ether (6BIGOE; 1) were identified as potent inhibitors of glycogen synthase kinase-3ß (GSK-3ß). These inhibitors suppress the release of pro-inflammatory cytokines and prostaglandins (PG) from human monocytes. However, indirubin derivatives target several protein kinases such as cyclin-dependent kinases (CDKs) which has been a major concern for their application in inflammation therapy. Here, we report on a library of 13 5-bromo-substituted indirubin derivatives that have been designed to improve potency and target selectivity. Side-by-side comparison of reference compound 1 (6BIGOE) with 5-bromo derivatives revealed its isomer 2 (5BIGOE), as the most potent derivative able to supress pro-inflammatory cytokine and PG release in lipopolysaccharide-stimulated human monocytes. Analysis of protein kinase inhibition in intact monocytes, supported by our in silico findings, proposed higher selectivity of 1 for GSK-3ß inhibition with lesser potency against CDKs 8 and 9. In contrast, 2 supressed the activity of these CDKs with higher effectiveness than GSK-3ß, representing additional targets of indirubins within the inflammatory response. Encapsulation of 1 and 2 into polymer-based nanoparticles (NP) improved their pharmacological potential. In conclusion, the 5- and 6-brominated indirubins 1 and 2 as dual GSK-3ß and CDK8/9 inhibitors represent a novel concept for intervention with inflammatory disorders.

Sustainability in Drug and Nanoparticle Processing.

The formulation of drugs in poly(lactic-co-glycolic acid) (PLGA) nanoparticles can be accomplished by various methods, with nanoprecipitation and nanoemulsion being among the most commonly used manufacturing techniques to provide access to high-quality nanomaterials with reproducible quality. Current trends turned to sustainability and green concepts leading to a re-thinking of these techniques, particularly as the conventional solvents for the dissolution of the polymer suffer from limitations like hazards for human health and natural environment. This chapter gives an overview about the different excipients used in classical nanoformulations with a special focus on the currently applied organic solvents. As alternatives, the status quo of green, sustainable, and alternative solvents regarding their application, advantages, and limitations will be highlighted as well as the role of physicochemical solvent characteristics like water miscibility, viscosity, and vapor pressure for the selection of the formulation process, and for particle characteristics. New alternative solvents will be introduced for PLGA nanoparticle formation and compared regarding particle characteristics and biological effects as well as for in situ particle formation in a matrix consisting of nanocellulose. Conclusively, new alternative solvents are available that present a significant advancement toward the replacement of organic solvents in PLGA nanoparticle formulations.

Longitudinal Assessment of Blood-Based Inflammatory, Neuromuscular, and Neurovascular Biomarker Profiles in Intensive Care Unit-Acquired Weakness: A Prospective Single-Center Cohort Study.

BACKGROUND: The diagnosis of intensive care unit (ICU)-acquired weakness (ICUAW) and critical illness neuromyopathy (CINM) is frequently hampered in the clinical routine. We evaluated a novel panel of blood-based inflammatory, neuromuscular, and neurovascular biomarkers as an alternative diagnostic approach for ICUAW and CINM. METHODS: Patients admitted to the ICU with a Sequential Organ Failure Assessment score of ≥ 8 on 3 consecutive days within the first 5 days as well as healthy controls were enrolled. The Medical Research Council Sum Score (MRCSS) was calculated, and motor and sensory electroneurography (ENG) for assessment of peripheral nerve function were performed at days 3 and 10. ICUAW was defined by an MRCSS < 48 and CINM by pathological ENG alterations, both at day 10. Blood samples were taken at days 3, 10, and 17 for quantitative analysis of 18 different biomarkers (white blood cell count, C-reactive protein, procalcitonin, C-terminal agrin filament, fatty-acid-binding protein 3, growth and differentiation factor 15, syndecan 1, troponin I, interferon-γ, tumor necrosis factor-α, interleukin-1α [IL-1α], IL-1ß, IL-4, IL-6, IL-8, IL-10, IL-13, and monocyte chemoattractant protein 1). Results of the biomarker analysis were categorized according to the ICUAW and CINM status. Clinical outcome was assessed after 3 months. RESULTS: Between October 2016 and December 2018, 38 critically ill patients, grouped into ICUAW (18 with and 20 without) and CINM (18 with and 17 without), as well as ten healthy volunteers were included. Biomarkers were significantly elevated in critically ill patients compared to healthy controls and correlated with disease severity and 3-month outcome parameters. However, none of the biomarkers enabled discrimination of patients with and without neuromuscular impairment, irrespective of applied classification. CONCLUSIONS: Blood-based biomarkers are generally elevated in ICU patients but do not identify patients with ICUAW or CINM. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02706314.

Medium supplementation with human, but not fetal calf serum facilitates endocytosis of PLGA nanoparticles by human primary B-lymphocytes via complement opsonization.

The "biological identity" of nanoparticles (NPs) is governed by a shell consisting of various biomolecules that is formed upon exposure to biological media, the so-called biomolecule corona. Consequently, supplementation of cell culture media with e.g. different sera is likely to affect interactions between cells and NPs ex-vivo, especially endocytosis. We aimed to investigate the differential impact of human and fetal-bovine serum on the endocytosis of poly (lactic-co-glycolic acid) NPs by human peripheral blood mononuclear cells via flow cytometry. Furthermore, we employed different methods to inhibit endocytosis, providing mechanistic insights. The resulting biomolecule corona was characterized via denaturing gel electrophoresis. We found profound differences between human and fetal bovine serum regarding the endocytosis of fluorescently labeled PLGA nanoparticles by different classes of human leukocytes. Uptake by B-lymphocytes was particularly sensitive. We further present evidence, that these effects are mediated by a biomolecule corona. We demonstrate to our knowledge for the first time that the complement is an important contributor to the endocytosis of non-surface-engineered PLGA-nanoparticles prepared via emulsion solvent evaporation by human immune cells. Our data demonstrates that results obtained with xenogeneic culture supplements such as fetal bovine serum may have to be interpreted with caution.

Efficacy of dietary vitamin D3 and 25(OH)D3 on reproductive capacities, growth performance, immunity and bone development in pigs.

Vitamin D3 (Vit D3) and 25(OH)D3 are used as dietary sources of active vitamin D (1,25(OH)2D3) in pig husbandry. Although acting primarily on intestine, kidney and bone, their use in pig nutrition has shown a wide range of effects also in peripheral tissues. However, there is an ambiguity in the existing literature about whether the effects of Vit D3 and 25(OH)D3 differ in attributing the molecular and phenotypic outcomes in pigs. We searched Web of Science and PubMed databases concerning the efficacy of Vit D3 in comparison with 25(OH)D3 on pig physiology, i.e. reproductive capacities, growth performance, immunity and bone development. Dietary intake of Vit D3 or 25(OH)D3 did not influence the reproductive capacity of sows. Unlike Vit D3, the maternal intake of 25(OH)D3 significantly improved the growth performance of piglets, which might be attributed to maternally induced micronutrient efficiency. Consequently, even in the absence of maternal vitamin D supplementation, 25(OH)D3-fed offspring also demonstrated better growth than the offspring received Vit D3. Moreover, a similar superior impact of 25(OH)D3 was seen with respect to serum markers of innate and humoral immunity. Last but not least, supplements containing 25(OH)D3 were found to be more effective than Vit D3 to improve bone mineralisation and formation, especially in pigs receiving basal diets low in Ca and phosphorus. The insights are of particular value in determining the principal dietary source of vitamin D to achieve its optimum utilisation efficiency, nutritional benefits and therapeutic potency and to further improve animal welfare across different management types.

Changes in bone biomarkers in response to different dosing regimens of cholecalciferol supplementation in children with chronic kidney disease.

BACKGROUND: The effect of different dosing regimens of cholecalciferol supplementation on bone biomarkers has not been studied in children with chronic kidney disease (CKD). METHODS: This is a post hoc analysis of a multi-center randomized controlled trial which included children with CKD stages 2-4 with vitamin D deficiency (25-hydroxy vitamin D (25OHD) < 30 ng/ml) randomized 1:1:1 to receive an equivalent dose of oral cholecalciferol as daily, weekly or monthly treatment. Markers of bone formation (bone alkaline phosphatase (BAP), procollagen I N terminal peptide (PINP)), bone resorption (tartarate-resistant acid phosphatase 5b (TRAP), C terminal telopeptide (CTX)), and osteocyte markers (intact fibroblast growth factor 23 (iFGF23), sclerostin) and soluble klotho were measured at baseline and after 3 months of intensive replacement therapy. The change in biomarkers and ratio of markers of bone formation to resorption were compared between treatment arms. BAP and TRAP were expressed as age- and sex-specific z-scores. RESULTS: 25OHD levels increased with cholecalciferol supplementation, with 85% achieving normal levels. There was a significant increase in the BAP/TRAP ratio (p = 0.04), iFGF23 (p = 0.004), and klotho (p = 0.002) with cholecalciferol therapy, but this was comparable across all three therapy arms. The BAPz was significantly higher in the weekly arm (p = 0.01). The change in 25OHD (Δ25OHD) inversely correlated with ΔPTH (r = - 0.4, p < 0.001). CONCLUSIONS: Although cholecalciferol supplementation was associated with a significant increase in bone formation, the three dosing regimens of cholecalciferol supplementation have a comparable effect on the bone biomarker profile, suggesting that they can be used interchangeably to suit the patient's needs and optimize adherence to therapy. A higher resolution version of the Graphical abstract is available as Supplementary information.

Naturally occurring stable calcium isotope ratios are a novel biomarker of bone calcium balance in chronic kidney disease.

Dysregulated calcium homeostasis is common in chronic kidney disease and causally associated with disorders of bone mineralization. However, radiological measures and biomarkers do not allow accurate evaluation of bone calcium balance. Non-radioactive calcium isotopes, 42Ca and 44Ca, are present in our diet and sequestered into body compartments following principles of kinetic isotope fractionation. Isotopically light 42Ca is preferentially incorporated into bone, while heavier 44Ca is excreted. The ratio (44/42Caserum) increases when bone formation exceeds resorption and vice versa, reflecting bone calcium balance. We measured these calcium isotopes by inductively coupled plasma mass-spectrometry in blood, urine and feces of 42 children with chronic kidney disease and 92 receiving dialysis therapy. We compared the isotope ratios with bone biomarkers and determined total bone mineral content by dual-energy x-ray absorptiometry and peripheral quantitative CT expressed as age-adjusted z-scores. The 44/42Caserum ratio positively correlated with serum calcium, 25-hydroxyvitamin D and alkaline phosphatases and inversely with serum parathyroid hormone and other bone resorption markers. The 44/42Caserum ratio positively correlated with age-adjusted z-scores of tibial trabecular bone mineral density and total bone mineral content measured by peripheral quantitative CT, and hip bone mineral density measured by dual-energy X-ray absorptiometry. Significant and independent predictors of total bone mineral content, measured by, were the 44/42Caserum ratio and parathyroid hormone. The 44/42Caserum ratio, repeated after four weeks, highly correlated with baseline values. When adjusted for calcium-containing medications and kidney impairment, the 44/42Caserum ratio in patients receiving dialysis was 157% lower than that of age-matched children and 29% lower than levels in elderly women with osteoporosis, implying significantly lower bone mineral content. Thus, calcium isotope ratios may provide a novel, sensitive and non-invasive method of assessing bone calcium balance in chronic kidney disease.

Determining the optimal cholecalciferol dosing regimen in children with CKD: a randomized controlled trial.

BACKGROUND: The optimal treatment regimen for correcting 25-hydroxyvitamin D (25OHD) deficiency in children with chronic kidney disease (CKD) is not known. We compared cholecalciferol dosing regimens for achieving and maintaining 25OHD concentrations ≥30 ng/mL in children with CKD stages 2-4. METHODS: An open-label, multicentre randomized controlled trial randomized children with 25OHD concentrations <30 ng/mL in 1:1:1 to oral cholecalciferol 3000 IU daily, 25 000 IU weekly or 100 000 IU monthly for 3 months (maximum three intensive courses). In those with 25OHD ≥30 ng/mL, 1000 IU cholecalciferol daily (maintenance course) was given for up to 9 months. Primary outcome was achieving 25OHD ≥30 ng/mL at the end of intensive phase treatment. RESULTS: Ninety children were randomized to daily (n = 30), weekly (n = 29) or monthly (n = 31) treatment groups. At the end of intensive phase, 70/90 (77.8%) achieved 25OHD ≥30 ng/mL; 25OHD concentrations were comparable between groups (median 44.3, 39.4 and 39.3 ng/mL for daily, weekly and monthly groups, respectively; P = 0.24) with no difference between groups for time to achieve 25OHD ≥30 ng/mL (P = 0.28). There was no change in calcium, phosphorus and parathyroid hormone, but fibroblast growth factor 23 (P = 0.002) and klotho (P = 0.001) concentrations significantly increased and were comparable in all treatment groups. Irrespective of dosing regimen, children with glomerular disease had 25OHD concentrations lower than non-glomerular disease (25.8 versus 41.8 ng/mL; P = 0.007). One child had a 25OHD concentration of 134 ng/mL, and 5.5% had hypercalcemia without symptoms of toxicity. CONCLUSION: Intensive treatment with oral cholecalciferol as daily, weekly or monthly regimens achieved similar 25OHD concentrations between treatment groups, without toxicity. Children with glomerular disease required higher doses of cholecalciferol compared with those with non-glomerular disease.

Drug delivery of 6-bromoindirubin-3'-glycerol-oxime ether employing poly(D,L-lactide-co-glycolide)-based nanoencapsulation techniques with sustainable solvents.

BACKGROUND: Insufficient solubility and stability of bioactive small molecules as well as poor biocompatibility may cause low bioavailability and are common obstacles in drug development. One example of such problematic molecules is 6-bromoindirubin-3'-glycerol-oxime ether (6BIGOE), a hydrophobic indirubin derivative. 6BIGOE potently modulates the release of inflammatory cytokines and lipid mediators from isolated human monocytes through inhibition of glycogen synthase kinase-3 in a favorable fashion. However, 6BIGOE suffers from poor solubility and short half-lives in biological aqueous environment and exerts cytotoxic effects in various mammalian cells. In order to overcome the poor water solubility, instability and cytotoxicity of 6BIGOE, we applied encapsulation into poly(D,L-lactide-co-glycolide) (PLGA)-based nanoparticles by employing formulation methods using the sustainable solvents Cyrene™ or 400 g/mol poly(ethylene glycol) as suitable technology for efficient drug delivery of 6BIGOE. RESULTS: For all preparation techniques the physicochemical characterization of 6BIGOE-loaded nanoparticles revealed comparable crystallinity, sizes of about 230 nm with low polydispersity, negative zeta potentials around - 15 to - 25 mV, and biphasic release profiles over up to 24 h. Nanoparticles with improved cellular uptake and the ability to mask cytotoxic effects of 6BIGOE were obtained as shown in human monocytes over 48 h as well as in a shell-less hen's egg model. Intriguingly, encapsulation into these nanoparticles fully retains the anti-inflammatory properties of 6BIGOE, that is, favorable modulation of the release of inflammation-relevant cytokines and lipid mediators from human monocytes. CONCLUSIONS: Our formulation method of PLGA-based nanoparticles by applying sustainable, non-toxic solvents is a feasible nanotechnology that circumvents the poor bioavailability and biocompatibility of the cargo 6BIGOE. This technology yields favorable drug delivery systems for efficient interference with inflammatory processes, with improved pharmacotherapeutic potential.

Surface Design Options in Polymer- and Lipid-Based siRNA Nanoparticles Using Antibodies.

The mechanism of RNA interference (RNAi) could represent a breakthrough in the therapy of all diseases that arise from a gene defect or require the inhibition of a specific gene expression. In particular, small interfering RNA (siRNA) offers an attractive opportunity to achieve a new milestone in the therapy of human diseases. The limitations of siRNA, such as poor stability, inefficient cell uptake, and undesired immune activation, as well as the inability to specifically reach the target tissue in the body, can be overcome by further developments in the field of nanoparticulate drug delivery. Therefore, types of surface modified siRNA nanoparticles are presented and illustrate how a more efficient and safer distribution of siRNA at the target site is possible by modifying the surface properties of nanoparticles with antibodies. However, the development of such efficient and safe delivery strategies is currently still a major challenge. In consideration of that, this review article aims to demonstrate the function and targeted delivery of siRNA nanoparticles, focusing on the surface modification via antibodies, various lipid- and polymer-components, and the therapeutic effects of these delivery systems.

[Functional rehabilitation after transfemoral amputation : Shaft prosthesis or endo-exo prosthesis?] / Funktionelle Rehabilitation nach Oberschenkelamputation : Schaftprothese oder Endo-Exo-Prothese?

BACKGROUND: After transfemoral amputation a prosthesis is required to restore autonomous standing and bipedal locomotion. Attachment of the prosthesis can be achieved either classically via socket suspension with a shaft in the stump or directly via implantation of an intramedullary transcutaneous femoral prosthesis (osseointegrated prosthesis). AIM: A fully instrumented gait analysis should enable objectification of the anticipated advantages of the EEP with respect to the gait pattern and individual mobility. MATERIAL AND METHODS: In two patients with a unilateral transfemoral amputation a comprehensive gait analysis was carried out prior to and 6 months (patient 1) or 11 and 20 months (patient 2) after switching from a socket prosthesis to an EEP. This was carried out in the Gait Realtime Analysis Interactive Lab (GRAIL), a fully instrumented gait laboratory with virtual reality and enables assessment close to the conditions of daily life. RESULTS: In both cases the gait analysis confirmed the advantages associated with an EEP for the transmission of force to the prosthesis and the accompanying improvement in gait symmetry.

3D optical scanning as an objective and reliable tool for volumetry of the foot and ankle region.

BACKGROUND: Edema development of the foot and ankle region should be evaluated by an objective measurement. We hypothesized, that 3D optical scanning of this region can serve as an alternative to clinically established measurement techniques. METHODS: Two investigators determined the volume by 3D optical scanning and the figure-of-eight method in a random order at 2 separate time points. Plots were created and ICCs were calculated for determination of reliability. The Pearson correlation coefficient served as a measure of the association between both measures. RESULTS: 40 healthy volunteers with mean age of 28.3±9.9 years underwent four sequences of measurements. The inter- and intraobserver reliability of both methods was excellent with high intraclass correlation coefficients (ICC 3,1). A strong correlation (r=0.96, P<0.001) between measured ankle volumes was noted. CONCLUSION: 3D optical scanning turned out to be more reliable than the figure-of-eight method in a preclinical set-up. A clinical use should be aimed at.

Bacterial-Like Nonribosomal Peptide Synthetases Produce Cyclopeptides in the Zygomycetous Fungus Mortierella alpina.

Fungi are traditionally considered a reservoir of biologically active natural products. However, an active secondary metabolism has long not been attributed to early-diverging fungi such as Mortierella Here, we report on the biosynthesis of two series of cyclic pentapeptides, the malpicyclins and malpibaldins, as products of Mortierella alpina ATCC 32222. The molecular structures of malpicyclins were elucidated by high-resolution tandem mass spectrometry (HR-MS/MS), Marfey's method, and one-dimensional (1D) and 2D nuclear magnetic resonance (NMR) spectroscopy. In addition, malpibaldin biosynthesis was confirmed by HR-MS. Genome mining and comparative quantitative real-time PCR (qRT-PCR) expression analysis pointed at two pentamodular nonribosomal peptide synthetases (NRPSs), malpicyclin synthetase MpcA and malpibaldin synthetase MpbA, as candidate biosynthetic enzymes. Heterologous production of the respective adenylation domains and substrate specificity assays proved promiscuous substrate selection and confirmed their respective biosynthetic roles. In stark contrast to known fungal NRPSs, MpbA and MpcA contain bacterial-like dual epimerase/condensation domains allowing the racemization of enzyme-tethered l-amino acids and the subsequent incorporation of d-amino acids into the metabolites. Phylogenetic analyses of both NRPS genes indicated a bacterial origin and a horizontal gene transfer into the fungal genome. We report on the as-yet-unexplored nonribosomal peptide biosynthesis in basal fungi which highlights this paraphylum as a novel and underrated resource of natural products.IMPORTANCE Fungal natural compounds are industrially produced, with application in antibiotic treatment, cancer medications, and crop plant protection. Traditionally, higher fungi have been intensively investigated concerning their metabolic potential, but reidentification of already known compounds is frequently observed. Hence, alternative strategies to acquire novel bioactive molecules are required. We present the genus Mortierella as representative of the early-diverging fungi as an underestimated resource of natural products. Mortierella alpina produces two families of cyclopeptides, designated malpicyclins and malpibaldins, respectively, via two pentamodular nonribosomal peptide synthetases (NRPSs). These enzymes are much more closely related to bacterial than to other fungal NRPSs, suggesting a bacterial origin of these NRPS genes in Mortierella Both enzymes were biochemically characterized and are involved in as-yet-unknown biosynthetic pathways of natural products in basal fungi. Hence, this report establishes early-diverging fungi as prolific natural compound producers and sheds light on the origin of their biosynthetic capacity.

Active vitamin D is cardioprotective in experimental uraemia but not in children with CKD Stages 3-5.

BACKGROUND: Uraemic cardiac remodelling is associated with vitamin D and Klotho deficiency, elevated fibroblast growth factor 23 (FGF23) and activation of the renin-angiotensin system (RAS). The cardioprotective properties of active vitamin D analogues in this setting are unclear. METHODS: In rats with 5/6 nephrectomy (5/6Nx) treated with calcitriol, the cardiac phenotype and local RAS activation were investigated compared with controls. A nested case-control study was performed within the Cardiovascular Comorbidity in Children with Chronic Kidney Disease (4C) study, including children with chronic kidney disease (CKD) Stages 3-5 [estimated glomerular filtration rate (eGFR) 25 mL/min/1.73 m2] treated with and without active vitamin D. Echocardiograms, plasma FGF23 and soluble Klotho (sKlotho) were assessed at baseline and after 9 months. RESULTS: In rats with 5/6Nx, left ventricular (LV) hypertrophy, LV fibrosis and upregulated cardiac RAS were dose-dependently attenuated by calcitriol. Calcitriol further stimulated FGF23 synthesis in bone but not in the heart, and normalized suppressed renal Klotho expression. In the 4C study cohort, treatment over a mean period of 9 months with active vitamin D was associated with increased FGF23 and phosphate and decreased sKlotho and eGFR compared with vitamin D naïve controls, whereas LV mass index did not differ between groups. CONCLUSIONS: Active vitamin D ameliorates cardiac remodelling and normalizes renal Klotho expression in 5/6Nx rats but does not improve the cardiac phenotype in children with CKD Stages 3-5. This discrepancy may be due to further enhancement of circulating FGF23 and faster progression of CKD associated with reduced sKlotho and higher serum phosphate in vitamin D-treated patients.

Anti-inflammatory celastrol promotes a switch from leukotriene biosynthesis to formation of specialized pro-resolving lipid mediators.

The pentacyclic triterpenoid quinone methide celastrol (CS) from Tripterygium wilfordii Hook. F. effectively ameliorates inflammation with potential as therapeutics for inflammatory diseases. However, the molecular mechanisms underlying the anti-inflammatory and inflammation-resolving features of CS are incompletely understood. Here we demonstrate that CS potently inhibits the activity of human 5-lipoxygenase (5-LOX), the key enzyme in pro-inflammatory leukotriene (LT) formation, in cell-free assays with IC50 = 0.19-0.49 µM. Employing metabololipidomics using ultra-performance liquid chromatography coupled to tandem mass spectrometry in activated human polymorphonuclear leukocytes or M1 macrophages we found that CS (1 µM) potently suppresses 5-LOX-derived products without impairing the formation of lipid mediators (LM) formed by 12-/15-LOXs as well as fatty acid substrate release. Intriguingly, CS induced the generation of 12-/15-LOX-derived LM including the specialized pro-resolving mediator (SPM) resolvin D5 in human M2 macrophages. Finally, intraperitoneal pre-treatment of mice with 10 mg/kg CS strongly impaired zymosan-induced LT formation and simultaneously elevated the levels of SPM and related 12-/15-LOX-derived LM in peritoneal exudates, spleen and plasma in vivo. Conclusively, CS promotes a switch from LT biosynthesis to formation of SPM which may underlie the anti-inflammatory and inflammation-resolving effects of CS, representing an interesting pharmacological strategy for intervention with inflammatory disorders.

Indole, Phenyl, and Phenol Groups: The Role of the Comonomer on Gene Delivery in Guanidinium Containing Methacrylamide Terpolymers.

This report highlights the importance of hydrophobic groups mimicking the side chains of aromatic amino acids, which are tryptophan, phenylalanine, and tyrosine, in guanidinium bearing poly(methacrylamide)s for the design of non-viral gene delivery agents. Guanidinium containing methacrylamide terpolymers are prepared by aqueous reversible addition-fragmentation chain transfer (aRAFT) polymerization with different hydrophobic monomers, N-(2-indolethyl)methacrylamide (IEMA), N-phenethylmethacrylamide (PhEMA), or N-(4-hydroxyphenethyl)methacrylamide (PhOHEMA) by aiming similar contents. The well-defined polymers are obtained with a molar mass of ≈15 000 g mol-1 and ≈1.1 dispersity. All terpolymers demonstrate almost comparable in vitro cell viability and hemocompatibility profiles independent of the type of side chain. Although they all form positively charged, enzymatically stable polyplexes with plasmid DNA smaller than 200 nm, the incorporation of the IEMA monomer improve these parameters by demonstrating a higher DNA binding affinity and forming nanoassemblies of about 100 nm. These physicochemical characteristics are correlated with increased transfection rates in CHO-K1 cells dependent on the type of the monomer and the nitrogen to phosphate (N/P) ratio of the polyplexes, as determined by luciferase reporter gene assays.

Incorporation of Indole Significantly Improves the Transfection Efficiency of Guanidinium-Containing Poly(Methacrylamide)s.

A highly efficient transfection agent is reported that is based on terpolymer consisting of N-(2-hydroxypropyl)methacrylamide (HPMA), N-(3-guanidinopropyl) methacrylamide (GPMA), and N-(2-indolethyl)methacrylamide monomers (IEMA) by analogy to the amphipathic cell-penetrating peptides containing tryptophan and arginine residues. The incorporation of the indole-bearing monomer leads to successful plasmid DNA condensation even at a nitrogen-to-phosphate (N/P) ratio of 1. The hydrodynamic diameter of polyplexes is determined to be below 200 nm for all N/P ratios. The transfection studies demonstrate a 200-fold increase of the transgene expression in comparison to P(HPMA-co-GPMA) with the same guanidinium content. This study reveals the strong potential of the indole group as a side-chain pendant group that can increase the cellular uptake of polymers and the transfection efficiency of the respective polyplexes.

Diabetes Mellitus and Hypertension-A Case of Sugar and Salt?

The majority of patients with diabetes mellitus (DM) have hypertension (HTN). A specific mechanism for the development of HTN in DM has not been described. In the Zucker, Endothel, und Salz (sugar, endothelium, and salt) study (ZEuS), indices of glucose metabolism and of volume regulation are recorded. An analysis of these parameters shows that glucose concentrations interfere with plasma osmolality and that changes in glycemic control have a significant impact on fluid status and blood pressure. The results of this study are discussed against the background of the striking similarities between the regulation of sugar and salt blood concentrations, introducing the view that DM is probably a sodium-retention disorder that leads to a state of hypervolemia.

Evaluation of fetuin-A as a predictor of outcome after surgery for osteoporotic fracture of the proximal femur.

BACKGROUND: In the elderly, osteoporotic fractures of the femur are associated with high morbidity and mortality. At the time of hospitalization and during pre-operative care identification of patients at risk for poor outcome despite an otherwise good clinical condition is challenging. We hypothesized that the serum concentration of fetuin-A during post-operative recovery might serve as a biomarker. METHODS: During a 15 months period patients admitted to our hospital for treatment of a femur fracture were registered on a voluntary basis and irrespective of age, underlying diseases and therapy. For all patients enrolled in this registry, blood was sampled for additional laboratory analysis. Patients with osteoporotic fractures were invited for follow-up examination about 2 years later. At this time, the functional outcome and clinical performance together with the handgrip strength as a surrogate measure of overall strength were assessed and the occurrence of additional fractures was recorded. Results from these assessments and the absence or presence of subsequent fractures were combined as summary score of outcome (SSO) and overall physical performance (oPP), a score derived by principal component analysis and relying on normally distributed data, only. RESULTS: 39 of 96 eligible patients were deceased during the follow-up period, while 45 consented to participate in the study. Patients with a SSO ≥ 17 pts were younger and had higher fetuin-A serum concentrations (each p < 0.05) during hospitalization compared to those with a SSO below 8 pts. Age at follow-up together with total serum protein and fetuin-A levels during post-operative recovery had significant influence on SSO and oPP. Fetuin-A at time of follow-up examination was not associated with outcome. CONCLUSIONS: Our results are in favor of fetuin-A as an important factor for fracture healing but do not support an association between fetuin-A at time of follow-up examination and either SSO or oPP.

FGF23-Mediated Activation of Local RAAS Promotes Cardiac Hypertrophy and Fibrosis.

Patients with chronic kidney disease (CKD) are prone to developing cardiac hypertrophy and fibrosis, which is associated with increased fibroblast growth factor 23 (FGF23) serum levels. Elevated circulating FGF23 was shown to induce left ventricular hypertrophy (LVH) via the calcineurin/NFAT pathway and contributed to cardiac fibrosis by stimulation of profibrotic factors. We hypothesized that FGF23 may also stimulate the local renin-angiotensin-aldosterone system (RAAS) in the heart, thereby further promoting the progression of FGF23-mediated cardiac pathologies. We evaluated LVH and fibrosis in association with cardiac FGF23 and activation of RAAS in heart tissue of 5/6 nephrectomized (5/6Nx) rats compared to sham-operated animals followed by in vitro studies with isolated neonatal rat ventricular myocytes and fibroblast (NRVM, NRCF), respectively. Uremic rats showed enhanced cardiomyocyte size and cardiac fibrosis compared with sham. The cardiac expression of Fgf23 and RAAS genes were increased in 5/6Nx rats and correlated with the degree of cardiac fibrosis. In NRVM and NRCF, FGF23 stimulated the expression of RAAS genes and induced Ngal indicating mineralocorticoid receptor activation. The FGF23-mediated hypertrophic growth of NRVM and induction of NFAT target genes were attenuated by cyclosporine A, losartan and spironolactone. In NRCF, FGF23 induced Tgfb and Ctgf, which were suppressed by losartan and spironolactone, only. Our data suggest that FGF23-mediated activation of local RAAS in the heart promotes cardiac hypertrophy and fibrosis.