Myo1g is required for efficient adhesion and migration of activated B lymphocytes to inguinal lymph nodes.

Cell migration is a dynamic process that involves adhesion molecules and the deformation of the moving cell that depends on cytoskeletal remodeling and actin-modulating proteins such as myosins. In this work, we analyzed the role of the class I Myosin-1 g (Myo1g) in migratory processes of LPS + IL-4 activated B lymphocytes in vivo and in vitro. In vivo, the absence of Myo1g reduced homing of activated B lymphocytes into the inguinal lymph node. Using microchannel chambers and morphology analysis, we found that the lack of Myo1g caused adhesion and chemotaxis defects. Additionally, deficiency in Myo1g causes flaws in adopting a migratory morphology. Our results highlight the importance of Myo1g during B cell migration.

Biped Gait Analysis based on Forward Kinematics Modeling using Quaternions Algebra

ABSTRACT Gait is the main locomotion way for human beings as an autonomous decision. Due to the increase in people with walking disabilities, the precision in gait analysis for purposes in clinical diagnosis, sports medicine or biomechanical research for the design of assistive technologies is of special relevance. The literature reports notable contributions in technological developments with diverse applications; and in some cases, algorithms for characterization and gait analysis; however, more studies related to gait kinematics are necessary, such as the solution proposed in this work. In this paper, we focus on studying the forward kinematics of the lower limbs in human gait, using in a novel way quaternions algebra as mathematical tool and comparative analysis with classical methods is established. Gait analysis unlike other works is carried out by evaluating the rotational and tilting movements of the pelvis, flexion-extension of the hip and knee; as well as dorsiflexion and plantarflexion of the ankle. Finally, an assessment of normal, mild crouch and severe crouch gaits in the three anatomical planes is performed; and a metric based on the Euclidean norm in the cartesian space is used to evaluate these gaits.

Myo1g is an active player in maintaining cell stiffness in B-lymphocytes.

B-lymphocytes are migrating cells that specialize in antigen presentation, antibody secretion, and endocytosis; these processes implicate the modulation of plasma membrane elasticity. Cell stiffness is a force generated by the interaction between the actin-cytoskeleton and the plasma membrane, which requires the participation of several proteins. These proteins include class I myosins, which are now considered to play a role in controlling membrane-cytoskeleton interactions. In this study, we identified the motor protein Myosin 1g (Myo1g) as a mediator of this phenomenon. The absence of Myo1g decreased the cell stiffness, affecting cell adhesion, cell spreading, phagocytosis, and endocytosis in B-lymphocytes. The results described here reveal a novel molecular mechanism by which Myo1g mediates and regulates cell stiffness in B-lymphocytes. © 2016 Wiley Periodicals, Inc.