A framework for transforming the professional identity and brand image of All Nurses as Leaders.

BACKGROUND: The professional identity and brand image of nurses as leaders have not kept pace with the roles and scope of contemporary nursing practice. PURPOSE: To provide a framework to transform the professional identity and brand image of nursing from a caring discipline to one of leaders. METHODS: A Consensus Development Workgroup (CDW) design was used between the International Society for Professional Identity in Nursing (ISPIN) and the Institute for Brand Image of Nursing (IBIN) to advance the concept of All Nurses as Leaders across all settings and the public domain. DISCUSSION: The goal is to occupy a position in the minds of all stakeholders that differentiates nursing in a manner that is positive, relevant, accurate, desirable, and consistent over time. CONCLUSION: Current outcomes are endorsements, evidence-based strategies, and a framework to deconstruct the current brand image and align it with the desired brand image of All Nurses as Leaders.

H2O2 activates G protein, α 12 to disrupt the junctional complex and enhance ischemia reperfusion injury.

The epithelial cell tight junction separates apical and basolateral domains and is essential for barrier function. Disruption of the tight junction is a hallmark of epithelial cell damage and can lead to end organ damage including renal failure. Herein, we identify Gα12 activation by H(2)O(2) leading to tight junction disruption and demonstrate a critical role for Gα12 activation during bilateral renal ischemia/reperfusion injury. Madin-Darby canine kidney (MDCK) cells with inducible Gα12 (Gα12-MDCK) and silenced Gα12 (shGα12-MDCK) were subjected to ATP depletion/repletion and H(2)O(2)/catalase as models of tight junction disruption and recovery by monitoring transepithelial resistance. In ATP depleted cells, barrier disruption and recovery was not affected by Gα12, but reassembly was accelerated by Gα12 depletion. In contrast, silencing of Gα12 completely protected cells from H(2)O(2)-stimulated barrier disruption, a response that rapidly occurred in control cells. H(2)O(2) activated Src and Rho, and Src inhibition (by PP2), but not Rho (by Y27632), protected cells from H(2)O(2)-mediated barrier disruption. Immunofluorescent and biochemical analysis showed that H(2)O(2) led to increased tyrosine phosphorylation of numerous proteins and altered membrane localization of tight junction proteins through Gα12/Src signaling pathway. Gα12 and Src were activated in vivo during ischemia/reperfusion injury, and transgenic mice with renal tubular QLα12 (activated mutant) expression were delayed in recovery and showed more extensive injury. Conversely, Gα12 knockout mice were nearly completely protected from ischemia/reperfusion injury. Taken together, these studies reveal that ROS stimulates Gα12 to activate injury pathways and identifies a therapeutic target for ameliorating ROS mediated injury.

Identification of an antithrombotic allosteric modulator that acts through helix 8 of PAR1.

G protein-coupled receptors (GPCRs) can assume multiple conformations and possess multiple binding sites. Whereas endogenous agonists acting at the orthosteric binding site stabilize the active receptor conformation, small molecules that act at nonorthosteric sites can stabilize alternative conformations. The large majority of these allosteric modulators associate with extracellular loops of GPCRs. The role of intracellular domains in mediating allosteric modulation is largely unknown. In screening a small-molecule library for inhibitors of platelet activation, we identified a family of compounds that modified PAR1-mediated granule secretion. The most potent inhibitory compound, termed JF5, also demonstrated noncompetitive inhibition of the α(2A)-adrenergic receptor. Aggregation studies using a battery of platelet GPCR agonists demonstrated that sensitivity to JF5 was limited to GPCRs that possessed a constrained eighth helix, as defined by a C-terminal palmitoylation site and interactions with TM7 and the i1 loop. Inhibition by JF5 was overcome in a PAR1 mutant in which the eighth helix was deleted, confirming a role for helix 8 in JF5 activity. Evaluation of downstream signaling showed that JF5 was selective with regard to G protein coupling, blocking signaling mediated by G(αq) but not G(α12). The compound inhibited thrombus formation in vivo following vascular injury with an IC(50) of ∼1 mg/kg. These results indicate a role for helix 8 in conferring sensitivity to small molecules, and show that this sensitivity can be exploited to control platelet activation during thrombus formation.

Gα12 activation in podocytes leads to cumulative changes in glomerular collagen expression, proteinuria and glomerulosclerosis.

Glomerulosclerosis is a common pathological finding that often progresses to renal failure. The mechanisms of chronic kidney disease progression are not well defined, but may include activation of numerous vasoactive and inflammatory pathways. We hypothesized that podocytes are susceptible to filtered plasma components, including hormones and growth factors that stimulate signaling pathways leading to glomerulosclerosis. Gα12 couples to numerous G-protein-coupled receptors (GPCRs) and regulates multiple epithelial responses, including proliferation, apoptosis, permeability and the actin cytoskeleton. Herein, we report that genetic activation of Gα12 in podocytes leads to time-dependent increases in proteinuria and glomerulosclerosis. To mimic activation of Gα12 pathways, constitutively active Gα12 (QL) was conditionally expressed in podocytes using Nphs2-Cre and LacZ/floxed QLα12 transgenic mice. Some QLα12(LacZ+/Cre+) mice developed proteinuria at 4-6 months, and most were proteinuric by 12 months. Proteinuria increased with age, and by 12-14 months, many demonstrated glomerulosclerosis with ultrastructural changes, including foot process fusion and both mesangial and subendothelial deposits. QLα12(LacZ+/Cre+) mice showed no changes in podocyte number, apoptosis, proliferation or Rho/Src activation. Real-time PCR revealed no significant changes in Nphs1, Nphs2, Cd2ap or Trpc6 expression, but Col4a2 message was increased in younger and older mice, while Col4a5 was decreased in older mice. Confocal microscopy revealed disordered collagen IVα1/2 staining in older mice and loss of α5 without changes in other collagen IV subunits. Taken together, these studies suggest that Gα12 activation promotes glomerular injury without podocyte depletion through a novel mechanism regulating collagen (α)IV expression, and supports the notion that glomerular damage may accrue through persistent GPCR activation in podocytes.

Polycystin-1 protein level determines activity of the Galpha12/JNK apoptosis pathway.

Mutations in PKD1 are the most common cause of autosomal dominant polycystic kidney disease (ADPKD). The protein product of PKD1 (polycystin-1 (PC1)) is a large transmembrane protein with a short intracellular C terminus that interacts with numerous signaling molecules, including Galpha(12). Cyst formation in ADPKD results from numerous cellular defects, including abnormal cilia, changes in polarity, and dysregulated apoptosis and proliferation. Recently, we reported increased apoptosis in Madin-Darby canine kidney (MDCK) cells through Galpha(12) stimulation of JNK and degradation of the anti-apoptotic protein Bcl-2 (Yanamadala, V., Negoro, H., Gunaratnam, L., Kong, T., and Denker, B. M. (2007) J. Biol. Chem. 282, 24352-24363). Herein, we confirm this pathway in Galpha(12)-silenced MDCK cells and utilize MDCK cell lines harboring either overexpressed or silenced PC1 to demonstrate that PC1 expression levels determine activity of the JNK/Bcl-2 apoptosis pathway. PC1-overexpressing MDCK cells were resistant to thrombin/Galpha(12)-stimulated apoptosis, JNK activation, and Bcl-2 degradation. In contrast, PC1-silenced MDCK cells displayed enhanced thrombin-induced apoptosis, JNK activity, and Bcl-2 degradation. In pulldown experiments, PC1 bound to Galpha(12), but not the related Galpha(13) subunit, and thrombin-stimulated MDCK cells led to increased interaction of Galpha(12) with the PC1 C terminus. In transient transfection assays, a PC1 C-terminal mutant lacking the G protein-binding domain was uncoupled from PC1-inhibited apoptosis. PC1 expression levels may be increased or decreased in ADPKD, and these findings suggest a mechanism in which levels of PC1 expression modulate Galpha(12)/JNK-stimulated apoptosis. Taken together, these findings are consistent with a set point model in which PC1 expression levels regulate specific G protein signaling pathways important to cyst development.

Case report of a pseudo-isodicentric chromosome 9 resulting in mosaic trisomy 9.

Due to the variable presentation of mosaic chromosomal abnormalities, cases such as this are needed to define the phenotypic spectrum. It also highlights the importance of chromosome analysis to identify structural abnormalities that result in aneuploidy.

Galpha12 regulates protein interactions within the MDCK cell tight junction and inhibits tight-junction assembly.

The polarized functions of epithelia require an intact tight junction (TJ) to restrict paracellular movement and to separate membrane proteins into specific domains. TJs contain scaffolding, integral membrane and signaling proteins, but the mechanisms that regulate TJs and their assembly are not well defined. Galpha12 (GNA12) binds the TJ protein ZO-1 (TJP1), and Galpha12 activates Src to increase paracellular permeability via unknown mechanisms. Herein, we identify Src as a component of the TJ and find that recruitment of Hsp90 to activated Galpha12 is necessary for signaling. TJ integrity is disrupted by Galpha12-stimulated Src phosphorylation of ZO-1 and ZO-2 (TJP2); this phosphorylation leads to dissociation of occludin and claudin 1 from the ZO-1 protein complex. Inhibiting Hsp90 with geldanamycin blocks Galpha12-stimulated Src activation and phosphorylation, but does not affect protein levels or the Galpha12-ZO-1 interaction. Using the calcium-switch model of TJ assembly and GST-TPR (GST-fused TPR domain of PP5) pull-downs of activated Galpha12, we demonstrate that switching to normal calcium medium activates endogenous Galpha12 during TJ assembly. Thrombin increases permeability and delays TJ assembly by activating Galpha12, but not Galpha13, signaling pathways. These findings reveal an important role for Galpha12, Src and Hsp90 in regulating the TJ in established epithelia and during TJ assembly.