A control theoretic paradigm for cell signaling networks: a simple complexity for a sensitive robustness

The fields of molecular biology and cell biology are being flooded with complex genomic and proteomic datasets of large dimensions. We now recognize that each molecule in the cell and tissue can no longer be viewed as an isolated entity. Instead, each molecule must be considered as one member of an interacting network. Consequently, there is an urgent need for mathematical models to understand the behavior of cell signaling networks in health and in disease.     

Valid and reliable instruments for arm-hand assessment at ICF activity level in persons with hemiplegia: a systematic review

Background

Loss of arm-hand performance due to a hemiparesis as a result of stroke or cerebral palsy (CP), leads to large problems in daily life of these patients. Assessment of arm-hand performance is important in both clinical practice and research. To gain more insight in e.g. effectiveness of common therapies for different patient populations with similar clinical characteristics, consensus regarding the choice and use of outcome measures is paramount. To guide this choice, an overview of available instruments is necessary. The aim of this systematic review is to identify, evaluate and categorize instruments, reported to be valid and reliable, assessing arm-hand performance at the ICF activity level in patients with stroke or cerebral palsy.

Methods

A systematic literature search was performed to identify articles containing instruments assessing arm-hand skilled performance in patients with stroke or cerebral palsy. Instruments were identified and divided into the categories capacity, perceived performance and actual performance. A second search was performed to obtain information on their content and psychometrics.

Results

Regarding capacity, perceived performance and actual performance, 18, 9 and 3 instruments were included respectively. Only 3 of all included instruments were used and tested in both patient populations. The content of the instruments differed widely regarding the ICF levels measured, assessment of the amount of use versus the quality of use, the inclusion of unimanual and/or bimanual tasks and the inclusion of basic and/or extended tasks.

Conclusions

Although many instruments assess capacity and perceived performance, a dearth exists of instruments assessing actual performance. In addition, instruments appropriate for more than one patient population are sparse. For actual performance, new instruments have to be developed, with specific focus on the usability in different patient populations and the assessment of quality of use as well as amount of use. Also, consensus about the choice and use of instruments within and across populations is needed.     

Multiple In Vitro and In Vivo Regulatory Effects of Budesonide in CD4+ T Lymphocyte Subpopulations of Allergic Asthmatics

Background

Increased activation and increased survival of T lymphocytes characterise bronchial asthma.

Objectives

In this study the effect of budesonide on T cell survival, on inducible co-stimulator T cells (ICOS), on Foxp3 and on IL-10 molecules in T lymphocyte sub-populations was assessed.

Methods

Cell survival (by annexin V binding) and ICOS in total lymphocytes, in CD4+/CD25+ and in CD4+/CD25- and Foxp3 and IL-10 in CD4+/CD25+ and in CD4+/CD25-cells was evaluated, by cytofluorimetric analysis, in mild intermittent asthmatics (n = 19) and in controls (n = 15). Allergen induced T lymphocyte proliferation and the in vivo effects of budesonide in mild persistent asthmatics (n = 6) were also explored.

Results

Foxp3 was reduced in CD4+/CD25- and in CD4+/CD25+ cells and ICOS was reduced in CD4+/CD25+ cells but it was increased in CD4+CD25-in asthmatics when compared to controls. In asthmatics, in vitro, budesonide was able to: 1) increase annexin V binding and to reduce ICOS in total lymphocytes; 2) increase annexin V binding and Foxp3 and to reduce ICOS in CD4+/CD25- cells; 3) reduce annexin V binding and to increase IL-10 and ICOS in CD4+/CD25+ cells; 4) reduce cell allergen induced proliferation. In vivo, budesonide increased ICOS in CD4+/CD25+ while it increased Foxp3 and IL-10 in CD4+/CD25+ and in CD4+/CD25- cells.

Conclusions

Budesonide modulates T cell survival, ICOS, Foxp3 and IL-10 molecules differently in T lymphocyte sub-populations. The findings provided shed light on new mechanisms by which corticosteroids, drugs widely used for the clinical management of bronchial asthma, control T lymphocyte activation.     

Critical dependence of blood-borne biomarker concentrations on the half-lives of their carrier proteins

Until recently, the low-abundance (LA) range of the serum proteome was an unexplored reservoir of diagnostic information. Today it is increasingly appreciated that a diagnostic goldmine of LA biomarkers resides in the blood stream in complexed association with more abundant higher molecular weight carrier proteins such as albumin and immunoglobulins. As we now look to the possibility of harvesting these LA biomarkers more efficiently through engineered nano-scale particles, mathematical approaches are needed in order to reveal the mechanisms by which blood carrier proteins act as molecular ‘mops’ for LA diagnostic cargo, and the functional relationships between bound LA biomarker concentrations and other variables of interest such as biomarker intravasation and clearance rates and protein half-lives in the bloodstream. Here we show, by simple mathematical modeling, how the relative abundance of large carrier proteins and their longer half-lives in the bloodstream work together to amplify the total blood concentration of these tiny biomarkers. The analysis further suggests that alterations in the production of biomarkers lead to gradual rather than immediate changes in biomarker levels in the blood circulation. The model analysis also points to the characteristics of artificial nano-particles that would render them more efficient harvesters of tumor biomarkers in the circulation, opening up possibilities for the early detection of curable disease, rather than simply better detection of advanced disease.     

Development of multiplexed protein profiling and detection using near infrared detection of reverse-phase protein microarrays

Protein microarrays have been recently employed for signal pathway profiling and high-throughput protein expression analysis. Reversephase arrays, where the array consists of immobilized analytes and lysates has especially shown promise in low abundance analyte detection and signal pathway profiling using phospho-specific antibodies. A limitation to current reverse phase array methodology is the inability to multiplex proteomic-based endpoints as each array can only report one analyte endpoint. In this study, we report on the use of a dual dye based approach that can effectively double the number of endpoints observed per array allowing, for example, both phosphospecific and total protein levels to be measured and analyzed at once. The method utilizes antibody bound dyes that emit in the infrared spectral region as a means of sensitive and specific detection.     

Human exposure to mycotoxins in Egypt

This investigation examined the exposure of Egyptian infants to Aflatoxin M₁ (AfM₁) and of lactating mothers to Aflatoxin B₁, using AfM₁ in human milk as a biomarker for exposure to AfB₁. The presence of ochratoxin A (OA) in human milk was also investigated to determine the levels of infants exposure to OA from human milk. The results indicated that AfM₁ was found in 66 (55 %) of 120 human milk samples with a mean of 0.3 ± 0.53 ng/mL (range 0.02 to 2.09 ng/mL). OA was found in 43 (35.8 %) of 120 human milk samples with a mean of 21.1 ± 13.7 ng/mL (range 5.07 to 45.01 ng/mL), which will cause a daily intake of OA from human milk exceeding the suggested tolerable dose of 5 ng/kg_-1 of OA body weight. On the other side AfM₁ was found in 25 % of blood samples (5 out of 20 samples), at a mean of 1.18 ng/mL, but it was detected only in one urine sample (1 out of 20 samples). OA was detected only in 2 out of 13 blood samples (15.4 %) with an average 3.67 ng/mL. Whereas OA was not detected in all analyzed urine samples.     

Utility of reverse phase protein arrays: applications to signalling pathways and human body arrays.

Protein microarrays offer a new means by which to conduct quantitative profiling of disease-associated proteins. The knowledge gained may provide novel strategies for early detection, diagnosis and therapeutic intervention. A variety of sophisticated approaches, including gene arrays, sequencing consortiums and large-scale two-dimensional gel electrophoresis, continue to generate lists of proteins potentially linked to disease aetiology and progression. The challenge is to evaluate quantitatively promising lead protein candidates using matched normal and diseased cell populations. In contrast to the antibody array, the reverse phase protein microarrays (RPPA) do not require labelling of cellular protein lysates, and constitute a sensitive high throughput platform for marker screening, pathophysiology investigation and therapeutic monitoring. In this paper, examples will be provided using RPPAs in the study of the apoptotic signalling cascade and in the evaluation of the expression of organ-specific protein makers using microdissected human organ cell lysates configured as 'human body arrays'.     

Biomarkers of toxicity in Clarias gariepinus exposed to sublethal concentrations of polycyclic aromatic hydrocarbons

Physiological, biochemical and histological indices in Clarias gariepinus broodstock, and teratogenic indices in embryos exposed to sublethal concentrations of naphthalene, phenanthrene and pyrene were investigated in 2014 using a static-renewal bioassay protocol. Phenanthrene (1.41 mg l^?1) was the most toxic, followed by pyrene (1.53 mg l^?1) and naphthalene (7.21 mg l^?1), based on 96 h LC50 values. Hepatosomatic indices were significantly higher in naphthalene- and pyrene-treated males compared with solvent controls, whereas fecundity in females was significantly lower by factors of 2.4 (naphthalene), 2.8 (phenanthrene) and 2.4 (pyrene), compared with controls. Catalase levels were lower in female phenanthrene-treated fish compared with controls. Histological alterations observed in PAH-treated fish include oedema, inflammatory cells, epithelial lifting and hyperplasia in the gills, vacuolation, haemosiderin pigments and sinusoidal congestion in the liver, and degenerated zona radiata in the ovary. Teratogenic effects were not observed, as evidenced by the lack of histological alterations in embryos spawned from pre-exposed broodstock. Sex-specific responses and the utility of biomarkers at cellular and individual levels of organisation are therefore demonstrated for holistic evaluations of polycyclic aromatic hydrocarbons in ecotoxicological studies.     

The β3‐integrin endothelial adhesome regulates microtubule‐dependent cell migration

Integrin β3 is seen as a key anti‐angiogenic target for cancer treatment due to its expression on neovasculature, but the role it plays in the process is complex; whether it is pro‐ or anti‐angiogenic depends on the context in which it is expressed. To understand precisely β3's role in regulating integrin adhesion complexes in endothelial cells, we characterised, by mass spectrometry, the β3‐dependent adhesome. We show that depletion of β3‐integrin in this cell type leads to changes in microtubule behaviour that control cell migration. β3‐integrin regulates microtubule stability in endothelial cells through Rcc2/Anxa2‐driven control of active Rac1 localisation. Our findings reveal that angiogenic processes, both in vitro and in vivo, are more sensitive to microtubule targeting agents when β3‐integrin levels are reduced.