Clinical Proteomics: From Biological Sample to Clinical Exploitation

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Extensive differential protein phosphorylation as intraerythrocytic Plasmodium falciparumschizonts develop into extracellular invasive merozoites

Pathology of the most lethal form of malaria is caused by Plasmodium falciparum asexual blood stages and initiated by merozoite invasion of erythrocytes. We present a phosphoproteome analysis of extracellular merozoites revealing 1765 unique phosphorylation sites including 785 sites not previously detected in schizonts. All MS data have been deposited in the ProteomeXchange with identifier PXD001684 (http://proteomecentral.proteomexchange.org/dataset/PXD001684). The observed differential phosphorylation between extra and intraerythrocytic life-cycle stages was confirmed using both phospho-site and phospho-motif specific antibodies and is consistent with the core motif [K/R]xx[pS/pT] being highly represented in merozoite phosphoproteins. Comparative bioinformatic analyses highlighted protein sets and pathways with established roles in invasion. Within the merozoite phosphoprotein interaction network a subnetwork of 119 proteins with potential roles in cellular movement and invasion was identified and suggested that it is coregulated by a further small subnetwork of protein kinase A (PKA), two calcium-dependent protein kinases (CDPKs), a phosphatidyl inositol kinase (PI3K), and a GCN2-like elF2-kinase with a predicted role in translational arrest and associated changes in the ubquitinome. To test this notion experimentally, we examined the overall ubiquitination level in intracellular schizonts versus extracellular merozoites and found it highly upregulated in merozoites. We propose that alterations in the phosphoproteome and ubiquitinome reflect a starvation-induced translational arrest as intracellular schizonts transform into extracellular merozoites

Feasibility of a second iteration wrist and hand supported training system for self-administered training at home in chronic stroke

Telerehabilitation allows continued rehabilitation at home after discharge. The use of rehabilitation technology supporting wrist and hand movements within a motivational gaming environment could enable patients to train independently and ultimately serve as a way to increase the dosage of practice. This has been previously examined in the European SCRIPT project using a first prototype, showing potential feasibility, although several usability issues needed further attention. The current study examined feasibility and clinical changes of a second iteration training system, involving an updated wrist and hand supporting orthosis and larger variety of games with respect to the first iteration. Nine chronic stroke patients with impaired arm and hand function were recruited to use the training system at home for six weeks. Evaluation of feasibility and arm and hand function were assessed before and after training. Median weekly training duration was 113 minutes. Participants accepted the six weeks of training (median Intrinsic Motivation Inventory = 4.4 points and median System Usability Scale = 73%). After training, significant improvements were found for the Fugl Meyer assessment, Action Research Arm Test and self-perceived amount of arm and hand use in daily life. These findings indicate that technology-supported arm and hand training can be a promising tool for self-administered practice at home after stroke.Final Accepted Versio

Plasmodium falciparum infection induces dynamic changes in the erythrocyte phospho-proteome

The phosphorylation status of red blood cell proteins is strongly altered during the infection by the malaria parasite Plasmodium falciparum. We identify the key phosphorylation events that occur in the erythrocyte membrane and cytoskeleton during infection, by a comparative analysis of global phospho-proteome screens between infected (obtained at schizont stage) and uninfected RBCs. The meta-analysis of reported mass spectrometry studies revealed a novel compendium of 495 phosphorylation sites in 182 human proteins with regulatory roles in red cell morphology and stability, with about 25% of these sites specific to infected cells. A phosphorylation motif analysis detected 7 unique motifs that were largely mapped to kinase consensus sequences of casein kinase II and of protein kinase A/protein kinase C. This analysis highlighted prominent roles for PKA/PKC involving 78 phosphorylation sites. We then compared the phosphorylation status of PKA (PKC) specific sites in adducin, dematin, Band 3 and GLUT-1 in uninfected RBC stimulated or not by cAMP to their phosphorylation status in iRBC. We showed cAMP-induced phosphorylation of adducin S59 by immunoblotting and we were able to demonstrate parasite-induced phosphorylation for adducin S726, Band 3 and GLUT-1, corroborating the protein phosphorylation status in our erythrocyte phosphorylation site compendium

Detection of the intention to grasp during reach movements

IntroductionSoft-robotic gloves have been developed to enhance grip to support stroke patients during daily life tasks. Studies showed that users perform tasks faster without the glove as compared to with the glove. It was investigated whether it is possible to detect grasp intention earlier than using force sensors to enhance the performance of the glove.MethodsThis was studied by distinguishing reach-to-grasp movements from reach movements without the intention to grasp, using minimal inertial sensing and machine learning. Both single-user and multi-user support vector machine classifiers were investigated. Data were gathered during an experiment with healthy subjects, in which they were asked to perform grasp and reach movements.ResultsExperimental results show a mean accuracy of 98.2% for single-user and of 91.4% for multi-user classification, both using only two sensors: one on the hand and one on the middle finger. Furthermore, it was found that using only 40% of the trial length, an accuracy of 85...