The Role of Galpha13 in Integrin Signaling and Function

Integrins are known to transmit signaling in two directions: intracellular signaling stimulates conformational changes in the extracellular domain, leading to increased ligand affinity (inside-out signaling). Conversely, ligand binding in the extracellular domain of integrins transmit signals into the cell, leading to a cascade of signaling events that stimulate cell spreading, retraction, migration, and proliferation (outside-in signaling). The mechanism of integrin outside-in signaling has been unclear. We showed here that Galpha13 directly bound to the integrin beta3 cytoplasmic domain and that Galpha13-integrin interaction was promoted by ligand binding to the integrin alphaIIbbeta3 and by GTP loading of Galpha13. We showed that integrin ligation mediates thrombus formation and outside-in signaling, which requires Galpha13 and greatly expands thrombi. Our studies also demonstrated that Galpha13 and talin bind to mutually exclusive but distinct sites within the integrin beta3 cytoplasmic domain in opposing waves. The first talin-binding wave mediates inside-out signaling and also ligand-induced integrin activation, but is not required for outside-in signaling. Integrin ligation induces transient talin dissociation and Galpha13 binding to an EXE motif, which selectively mediates outside-in signaling and platelet spreading. The second talin-binding wave is associated with clot retraction. An EXE-motif-based inhibitor of Galpha13–integrin interaction selectively abolishes outside-in signaling without affecting integrin ligation, and suppresses occlusive arterial thrombosis without affecting bleeding time. Thus, we have discovered a new mechanism for the directional switch of integrin signaling and, on the basis of this mechanism, designed a new antithrombotic drug that does not cause bleeding. Secondly, we showed that the Galpha13 binding is important in integrin-dependent cell migration. We showed that interaction between Galpha13 and the beta1 subunit plays a critical role in beta1-dependent cell migration. We further showed that the Galpha13-beta1 interaction mediates beta1 integrin–dependent Src activation and transient RhoA inhibition during initial cell adhesion, which is in contrast to the role of Galpha13 in mediating GPCR-dependent RhoA activation. These data indicate that Galpha13 plays dynamic roles in both stimulating RhoA via a GPCR pathway and inhibiting RhoA via an integrin signaling pathway. This dynamic regulation of RhoA activity is critical for cell migration on beta1 integrin ligands

Prevention of Burnout Syndrom among Early Intervention Advisors

The bachelor thesis deals with the issue of prevention of burnout syndrome, what are the possibilities and methods that can be used in the context of personality and organization. The possibilities and methods of prevention of burnout syndrome were investigated on early care advisors in the Early Care Kuk, located in Pilsen. This document is conceived in two parts, theoretical and practical. The aim of the work was to find out which areas of prevention of burnout syndrome are priority for the early care advisors of the given center. The theoretical part describes the issue of burnout syndrome. It defines the term of burnout syndrome, vulnerable groups of people, it also deals with the risk factors that contribute to the burnout syndrome and describes the most frequent signs, symptoms and phases that are typical for the burnout syndrome. Subsequently, in the theoretical part is located a chapter on prevention at the level of personality and prevention at the organization level. The last chapter of the theoretical part is focused on early care, explanation of the concept, definition of rights and duties of early care advisors and the current state of early care in the Czech Republic. The practical part is elaborated in the form of qualitative research. In the survey were used the polling method and the interview technique according to the instructions. The survey was attended by 3 informants who were selected according to the quota selection method. The data obtained from the interviews was evaluated by the clustering method. Research has shown that early care advisors of the given center are familiar with the problematics of burnout syndrome and its prevention. Prevention options at the personality level are used individually. At the organization level, they use prevention options mainly in the form of supervision, intervision and further education. The research also showed that early care advisors of the given center perceive good workplace relationships and mutual support and respect as a key components of burnout syndrome prevention

The distribution of distance between movies.

<p>The distribution of distance between movies.</p

Bipartite hyper-network that is constructed by movie set, user set and the relation between users and movies.

<p>r_ix is the rating that user <i>i</i> votes for movie <i>x</i>.</p

Hyper-network in which user is treated as node and movie as hyper-edge.

<p>Hyper-network in which user is treated as node and movie as hyper-edge.</p

Aqueous and Nonaqueous Electrochemical Sensing on Whole-Teflon Chip

Whole-Teflon microfluidic chips integrated with gold microelectrodes were successfully fabricated for the first time. The surface morphology of electroless plated gold electrode was characterized with optical microscopy and scanning electron microscopy, while its electrochemical performance was investigated using cyclic voltammetry in both aqueous and nonaqueous solutions. The robustness and stability of this whole-Teflon chip were demonstrated by performing long-term hydrodynamic cyclic voltammetry in dichloromethane (DCM). Quantitative detection of 4-chloroaniline in DCM using square wave voltammetry was conducted to corroborate the potential application of this device for environmental pollutant sensing

The RMSE of prediction as a function of parameter <i>η</i>.

<p><i>η</i> is the maximal number of h-neighbors without rating from predicting user <i>i</i> before <i>k</i> h-neighbors are received. The results are with <i>k</i> = 7.</p

Network that is composed of user nodes and movie nodes. Movie ratings from users are the connections between users and movies.

<p>Network that is composed of user nodes and movie nodes. Movie ratings from users are the connections between users and movies.</p

The size of cliques vs. the number of corresponding networks.

<p>The size of cliques vs. the number of corresponding networks.</p

The distribution of RMSE of ratings that users voted for the first-order h-neighbor clique.

<p>The distribution of RMSE of ratings that users voted for the first-order h-neighbor clique.</p