Transmembrane adaptor protein WBP1L regulates CXCR4 signalling and murine haematopoiesis

WW domain binding protein 1‐like (WBP1L), also known as outcome predictor of acute leukaemia 1 (OPAL1), is a transmembrane adaptor protein, expression of which correlates with ETV6‐RUNX1 (t(12;21)(p13;q22)) translocation and favourable prognosis in childhood leukaemia. It has a broad expression pattern in haematopoietic and in non‐haematopoietic cells. However, its physiological function has been unknown. Here, we show that WBP1L negatively regulates signalling through a critical chemokine receptor CXCR4 in multiple leucocyte subsets and cell lines. We also show that WBP1L interacts with NEDD4‐family ubiquitin ligases and regulates CXCR4 ubiquitination and expression. Moreover, analysis of Wbp1l‐deficient mice revealed alterations in B cell development and enhanced efficiency of bone marrow cell transplantation. Collectively, our data show that WBP1L is a novel regulator of CXCR4 signalling and haematopoiesis.     

Trade in the Decade Following the Collapse of the USSR

In Soviet times, Moscow was a consumers’ oasis in a country of rampant scarcity. Millions of workers and peasants from all the free republics met in the capital of the unbreakable Union to stock up on delicacies, foreign goods, and all the things not available in the national hinterland. As new markets with a certain degree of specialization emerged, this introduced more stringent terms of trade and other measures aimed at eliminating the negative impact of commerce on the environment and improving the sanitary condition of the area, as well as improving traffic conditions and the general appearance of the environment. The authors analyze the space of commerce during the Soviet Union’s existence and after its collapse, and show how popular attitudes changed.     

Detection of Borrelia burgdorferi Sensu Stricto ospC Alleles Associated with Human Lyme Borreliosis Worldwide in Non-Human-Biting Tick Ixodes affinis and Rodent Hosts in Southeastern United States

Comparative analysis of ospC genes from 127 Borrelia burgdorferi sensu stricto strains collected in European and North American regions where Lyme disease is endemic and where it is not endemic revealed a close relatedness of geographically distinct populations. ospC alleles A, B, and L were detected on both continents in vectors and hosts, including humans. Six ospC alleles, A, B, L, Q, R, and V, were prevalent in Europe; 4 of them were detected in samples of human origin. Ten ospC alleles, A, B, D, E3, F, G, H, H3, I3, and M, were identified in the far-western United States. Four ospC alleles, B, G, H, and L, were abundant in the southeastern United States. Here we present the first expanded analysis of ospC alleles of B. burgdorferi strains from the southeastern United States with respect to their relatedness to strains from other North American and European localities. We demonstrate that ospC genotypes commonly associated with human Lyme disease in European and North American regions where the disease is endemic were detected in B. burgdorferi strains isolated from the non-human-biting tick Ixodes affinis and rodent hosts in the southeastern United States. We discovered that some ospC alleles previously known only from Europe are widely distributed in the southeastern United States, a finding that confirms the hypothesis of transoceanic migration of Borrelia species.     

The Rare ospC Allele L of Borrelia burgdorferi Sensu Stricto,Commonly Found among Samples Collected in a Coastal Plain Area of the Southeastern United States,Is Associated with Ixodes affinis Ticks and Local Rodent Hosts Peromyscus gossypinus and Sigmodon hispidus

The rare ospC allele L was detected in 30% of Borrelia burgdorferi sensu stricto strains cultured from a tick species, Ixodes affinis, and two rodent host species, Peromyscus gossypinus and Sigmodon hispidus, collected in a coastal plain area of Georgia and South Carolina, in the southeastern United States.     

Cardiovascular Complications Secondary to Graves’ Disease: A Prospective Study from Ukraine

Background

Graves’ disease (GD) is a common cause of hyperthyroidism resulting in development of thyrotoxic heart disease (THD).

Objectives

to assess cardiovascular disorders and health related quality of life (HRQoL) in patients with THD secondary to GD.

Patients and Methods

All patients diagnosed with THD secondary to GD between January 2011 and December 2013 were eligible for this study. Clinical assessment was performed at baseline and at the follow-up visit after the restoring of euthyroid state. HRQoL was studied with a questionnaire EQ-5D-5L.

Results

Follow-up data were available for 61 patients, but only 30 patients with THD secondary to GD were consented to participate in investigation of their HRQoL. The frequency of cardiovascular complications was significantly reduced as compared before and after the antithyroid therapy as follows: resting heart rate (122 vs. 74 bpm), blood pressure: systolic (155 vs. 123 mm Hg), diastolic (83 vs. 66 mm Hg), supraventricular premature contractions (71% vs. 7%), atrial fibrillation (72% vs. 25%), congestive heart failure (69% vs. 20%), thyrotoxic cardiomyopathy (77% vs. 26%), all p<0.01. Anti-TSH receptor antibodies were determined as independent predictor of left ventricular geometry changes, (b-coefficient = 0.04, 95%CI 0.01–0.07, p = 0.02). HRQoL was improved in all domains and self-rated health increased from 43 to 75 units by visual analogue score (p<0.001).

Conclusions

Restoring of euthyroid state in patients with GD is associated with significant elimination of cardiovascular disorders and improvement of HRQoL. To our knowledge this is the first study evaluating Ukrainian patients with THD secondary to GD with focus on HRQoL.     

If Cell Mechanics Can Be Described by Elastic Modulus: Study of Different Models and Probes Used in Indentation Experiments

Here we investigated the question whether cells, being highly heterogeneous objects, could be described with the elastic modulus (effective Young’s modulus) in a self-consistent way. We performed a comparative analysis of the elastic modulus derived from the indentation data obtained with atomic force microscopy (AFM) on human cervical epithelial cells (both normal and cancerous). Both sharp (cone) and dull (2500-nm radius sphere) AFM probes were used. The indentation data were processed through different elastic models. The cell was approximated as a homogeneous elastic medium that had either 1), smooth hemispherical boundary (Hertz/Sneddon models) or 2), the boundary covered with a layer of glycocalyx and membrane protrusions (“brush” models). Consistency of these approximations was investigated. Specifically, we tested the independence of the elastic modulus of the indentation depth, which is assumed in these models. We demonstrated that only one model showed consistency in treating cells as a homogeneous elastic medium, namely, the brush model, when processing the indentation data collected with the dull AFM probe. The elastic modulus demonstrated strong depth dependence in all models: Hertz/Sneddon models (no brush taken into account), and when the brush model was applied to the data collected with sharp conical probes. We conclude that it is possible to describe the elastic properties of the cell body by means of an effective elastic modulus, used in a self-consistent way, when using the brush model to analyze data collected with a dull AFM probe. The nature of these results is discussed.     

If Cell Mechanics Can Be Described by Elastic Modulus: Study of Different Models and Probes Used in Indentation Experiments

Here we investigated the question whether cells, being highly heterogeneous objects, could be described with the elastic modulus (effective Young’s modulus) in a self-consistent way. We performed a comparative analysis of the elastic modulus derived from the indentation data obtained with atomic force microscopy (AFM) on human cervical epithelial cells (both normal and cancerous). Both sharp (cone) and dull (2500-nm radius sphere) AFM probes were used. The indentation data were processed through different elastic models. The cell was approximated as a homogeneous elastic medium that had either 1), smooth hemispherical boundary (Hertz/Sneddon models) or 2), the boundary covered with a layer of glycocalyx and membrane protrusions (“brush” models). Consistency of these approximations was investigated. Specifically, we tested the independence of the elastic modulus of the indentation depth, which is assumed in these models. We demonstrated that only one model showed consistency in treating cells as a homogeneous elastic medium, namely, the brush model, when processing the indentation data collected with the dull AFM probe. The elastic modulus demonstrated strong depth dependence in all models: Hertz/Sneddon models (no brush taken into account), and when the brush model was applied to the data collected with sharp conical probes. We conclude that it is possible to describe the elastic properties of the cell body by means of an effective elastic modulus, used in a self-consistent way, when using the brush model to analyze data collected with a dull AFM probe. The nature of these results is discussed.     

Fermentation and Cost-Effective 13C/15N Labeling of the Nonribosomal Peptide Gramicidin S for Nuclear Magnetic Resonance Structure Analysis

Gramicidin S (GS) is a nonribosomally synthesized decapeptide from Aneurinibacillus migulanus. Its pronounced antibiotic activity is attributed to amphiphilic structure and enables GS interaction with bacterial membranes. Despite its medical use for over 70 years, the peptide-lipid interactions of GS and its molecular mechanism of action are still not fully understood. Therefore, a comprehensive structural analysis of isotope-labeled GS needs to be performed in its biologically relevant membrane-bound state, using advanced solid-state nuclear magnetic resonance (NMR) spectroscopy. Here, we describe an efficient method for producing the uniformly ¹³C/¹⁵N-labeled peptide in a minimal medium supplemented by selected amino acids. As GS is an intracellular product of A. migulanus, we characterized the producer strain DSM 5759 (rough-convex phenotype) and examined its biosynthetic activity in terms of absolute and biomass-dependent peptide accumulation. We found that the addition of either arginine or ornithine increases the yield only at very high supplementing concentrations (1% and 0.4%, respectively) of these expensive ¹³C/¹⁵N-labeled amino acids. The most cost-effective production of ¹³C/¹⁵N-GS, giving up to 90 mg per gram of dry cell weight, was achieved in a minimal medium containing 1% ¹³C-glycerol and 0.5% ¹⁵N-ammonium sulfate, supplemented with only 0.025% of ¹³C/¹⁵N-phenylalanine. The 100% efficiency of labeling is corroborated by mass spectrometry and preliminary solid-state NMR structure analysis of the labeled peptide in the membrane-bound state.