BIGH3 modulates adhesion and migration of hematopoietic stem and progenitor cells

Cell adhesion and migration are important determinants of homing and development of hematopoietic stem and progenitor cells (HSPCs) in bone marrow (BM) niches. The extracellular matrix protein transforming growth factor-β (TGF-β) inducible gene H3 (BIGH3) is involved in adhesion and migration, although the effect of BIGH3 is highly cell type-dependent. BIGH3 is abundantly expressed by mesenchymal stromal cells, while its expression in HSPCs is relatively low unless induced by certain BM stressors. Here, we set out to determine how BIGH3 modulates HSPC adhesion and migration. We show that primary HSPCs adhere to BIGH3-coated substrates, which is, in part, integrin-dependent. Overexpression of BIGH3 in HSPCs and HL60 cells reduced the adhesion to the substrate fibronectin in adhesion assays, which was even more profound in electrical cell-substrate impedance sensing (ECIS) assays. Accordingly, the CXCL12 induced migration over fibronectin-coated surface was reduced in BIGH3-expressing HSPCs. The integrin expression profile of HSPCs was not altered upon BIGH3 expression. Although expression of BIGH3 did not alter actin polymerization in response to CXCL12, it inhibited the PMA-induced activation of the small GTPase RAC1 as well as the phosphorylation and activation of extracellular-regulated kinases (ERKs). Reduced activation of ERK and RAC1 may be responsible for the inhibition of cell adhesion and migration by BIGH3 in HSPCs. Induced BIGH3 expression upon BM stress may contribute to the regulation of BM homeostasis.     

Research into the (Cost-) effectiveness of the ketogenic diet among children and adolescents with intractable epilepsy: design of a randomized controlled trial

Background  

Epilepsy is a neurological disorder, characterized by recurrent unprovoked seizures which have a high impact on the individual as well as on society as a whole. In addition to the economic burden, epilepsy imposes a substantial burden on the patients and their surroundings. Patients with uncontrolled epilepsy depend heavily on informal care and on health care professionals. About 30% of patients suffer from drug-resistant epilepsy. The ketogenic diet can be a treatment of last resort, especially for children. The beneficial effect of the ketogenic diet has been proven, but information is lacking about its cost-effectiveness. In the current study we will evaluate the (cost-) effectiveness of the ketogenic diet in children and adolescents with intractable epilepsy.     

Increase in IL-21 producing T-cells in patients with systemic lupus erythematosus

Introduction  

Systemic lupus erythematosus (SLE) is an autoimmune disease accompanied by a disturbed T-cell balance skewed towards effector T-cells, in particular Th17-cells. The novel cytokine interleukin-21 (IL-21) is suggested to be crucial for triggering T-cell responses towards IL-17 producing cells. Thus, we aimed to investigate the ability of T-cells to produce IL-21 and IL-17 in SLE patients.     

Urine levels of HMGB1 in Systemic Lupus Erythematosus patients with and without renal manifestations

Introduction

Lupus nephritis (LN) is a severe and frequent manifestation of systemic lupus erythematosus (SLE). Its pathogenesis has not been fully elucidated but immune complexes are considered to contribute to the inflammatory pathology in LN. High Mobility Group Box 1 (HMGB1) is a nuclear non-histone protein which is secreted from different types of cells during activation and/or cell death and may act as a pro-inflammatory mediator, alone or as part of DNA-containing immune complexes in SLE. Urinary excretion of HMGB1 might reflect renal inflammatory injury. To assess whether urinary HMGB1 reflects renal inflammation we determined serum levels of HMGB1 simultaneously with its urinary levels in SLE patients with and without LN in comparison to healthy controls (HC). We also analyzed urinary HMGB1 levels in relation with clinical and serological disease activity.

Methods

The study population consisted of 69 SLE patients and 17 HC. Twenty-one patients had biopsy proven active LN, 15 patients had a history of LN without current activity, and 33 patients had non-renal SLE. Serum and urine levels of HMGB1 were both measured by western blotting. Clinical and serological parameters were assessed according to routine procedures. In 17 patients with active LN a parallel analysis was performed on the expression of HMGB1 in renal biopsies.

Results

Serum and urinary levels of HMGB1 were significantly increased in patients with active LN compared to patients without active LN and HC. Similarly, renal tissue of active LN patients showed strong expression of HMGB1 at cytoplasmic and extracellular sites suggesting active release of HMGB1. Serum and urinary levels in patients without active LN were also significantly higher compared to HC. Urinary HMGB1 levels correlated with SLEDAI, and showed a negative correlation with complement C3 and C4.

Conclusion

Levels of HMGB1 in urine of SLE patients, in particular in those with active LN, are increased and correlate with SLEDAI scores. Renal tissue of LN patients shows increased release of nuclear HMGB1 compared to control renal tissue. HMGB1, although at lower levels, is, however, also present in the urine of patients without active LN. These data suggest that urinary HMGB1 might reflect both local renal inflammation as well as systemic inflammation.     

The effect of three years of TNF alpha blocking therapy on markers of bone turnover and their predictive value for treatment discontinuation in patients with ankylosing spondylitis: a prospective longitudinal observational cohort study

Introduction

The aim of this study was to investigate the effect of three years of tumor necrosis factor-alpha (TNF-α) blocking therapy on bone turnover as well as to analyze the predictive value of early changes in bone turnover markers (BTM) for treatment discontinuation in patients with ankylosing spondylitis (AS).

Methods

This is a prospective cohort study of 111 consecutive AS outpatients who started TNF-α blocking therapy. Clinical assessments and BTM were assessed at baseline, three and six months, as well as at one, two, and three years. Z-scores of BTM were calculated to correct for age and gender. Bone mineral density (BMD) was assessed yearly.

Results

After three years, 72 patients (65%) were still using their first TNF-α blocking agent. In these patients, TNF-α blocking therapy resulted in significantly increased bone-specific alkaline phosphatase, a marker of bone formation; decreased serum collagen-telopeptide (sCTX), a marker of bone resorption; and increased lumbar spine and hip BMD compared to baseline. Baseline to three months decrease in sCTX Z-score (HR: 0.394, 95% CI: 0.263 to 0.591), AS disease activity score (ASDAS; HR: 0.488, 95% CI: 0.317 to 0.752), and physician''s global disease activity (HR: 0.739, 95% CI: 0.600 to 0.909) were independent inversely related predictors of time to treatment discontinuation because of inefficacy or intolerance. Early decrease in sCTX Z-score correlated significantly with good long-term response regarding disease activity, physical function and quality of life.

Conclusions

Three years of TNF-α blocking therapy results in a bone turnover balance that favors bone formation, especially mineralization, in combination with continuous improvement of lumbar spine BMD. Early change in sCTX can serve as an objective measure in the evaluation of TNF-α blocking therapy in AS, in addition to the currently used more subjective measures.     

Theory of the acoustic instability and behavior of the phase velocity of acoustic waves in a weakly ionized plasma

The amplification of acoustic waves due to the transfer of thermal energy from electrons to the neutral component of a glow discharge plasma is studied theoretically. It is shown that, in order for acoustic instability (sound amplification) to occur, the amount of energy transferred should exceed the threshold energy, which depends on the plasma parameters and the acoustic wave frequency. The energy balance equation for an electron gas in the positive column of a glow discharge is analyzed for conditions typical of experiments in which acoustic wave amplification has been observed. Based on this analysis, one can affirm that, first, the energy transferred to neutral gas in elastic electron-atom collisions is substantially lower than the threshold energy for acoustic wave amplification and, second, that the energy transferred from electrons to neutral gas in inelastic collisions is much higher than that transferred in elastic collisions and thus may exceed the threshold energy. It is also shown that, for amplification to occur, there should exist some heat dissipation mechanism more efficient than gas heat conduction. It is suggested that this may be convective radial mixing within a positive column due to acoustic streaming in the field of an acoustic wave. The features of the phase velocity of sound waves in the presence of acoustic instability are investigated.     

Biological macromolecule binding and anticancer activity of synthetic alkyne-containing l -phenylalanine derivatives

Herein, we described the synthesis of two l-phenylalanines α-derivatized with a terminal alkyne moiety whose structures differed by phenyl ring halogen substitution (two o-Cl in 1 vs. one p-Br in 2) and investigated their effect on biological macromolecules and living cells. We explored their interaction with quadruplex DNA (G4 DNA), using tel26 and c-myc as models, and bovine serum albumin (BSA). By CD spectroscopy, we found that 1 caused minor tel26 secondary structure changes, leading also to a slight thermal stabilization of this hybrid antiparallel/parallel G4 structure, while the c-myc parallel topology remained essentially unchanged upon 1 binding. Other CD evidences showed the ability of 1 to bind BSA, while molecular docking studies suggested that the same molecule could be housed into the hydrophobic cavity between sub-domains IIA, IIB, and IIIA of the protein. Furthermore, preliminary aggregation studies, based on concentration-dependent spectroscopic experiments, suggested the ability of 1 to aggregate forming noncovalent polymeric systems in aqueous solution. Differently from 1, the bromine-modified compound was able to bind Cu(II) ion, likely with the formation of a CuL2 complex, as found by UV spectroscopy. Finally, cell tests excluded any cytotoxic effect of both compounds toward normal cells, but showed slight antiproliferative effects of 2 on PC3 cancerous cells at 24 h, and of 1 on both T98G and MDA-MB-231 cancer cells at 48 h.     

Analysis of free amino acids in mammalian brain extracts

An optimized method for analysis of free amino acids using a modified lithium-citrate buffer system with a Hitachi L-8800 amino acid analyzer is described. It demonstrates clear advantages over the sodium-citrate buffer system commonly used for the analysis of protein hydrolysates. A sample pretreatment technique for amino acid analysis of brain extracts is also discussed. The focus has been placed on the possibility of quantitative determination of the reduced form of glutathione (GSH) with simultaneous analysis of all other amino acids in brain extracts. The method was validated and calibration coefficient (K _GSH) was determined. Examples of chromatographic separation of free amino acids in extracts derived from different parts of the brain are presented.     

Early atherosclerosis in systemic sclerosis and its relation to disease or traditional risk factors

Introduction  

Several systemic autoimmune diseases are associated with an increased prevalence of atherosclerosis which could not be explained by traditional risk factors alone. In systemic sclerosis (SSc), microvascular abnormalities are well recognized. Previous studies have suggested an increased prevalence of macrovascular disease as well. We compared patients with SSc to healthy controls for signs of early atherosclerosis by measuring intima-media thickness (IMT) of the common carotid artery in relation to traditional risk factors and markers of endothelial activation.