Regulation of human cardiac KCNQ1/KCNE1 channel by epidermal growth factor receptor kinase

The aim of the present study was to investigate whether/how the recombinant human cardiac I Ks could be regulated by epidermal growth factor receptor kinase in HEK 293 cells stably expressing hKCNQ1/hKCNE1 genes using the approaches of perforated patch clamp technique, immunoprecipitation and Western blot analysis. It was found that the broad spectrum isoflavone tyrosine kinase inhibitor genistein and the selective epidermal growth factor receptor kinase inhibitor tyrphostin AG556 suppressed the recombinant I Ks, and their inhibition was countered by the protein tyrosine phosphatase inhibitor orthovanadate. The Src-family kinase inhibitor PP2 reduced the current, but the effect was not antagonized by orthovanadate. Immunoprecipitation and Western blot analysis revealed that tyrosine phosphorylation level of hKCNQ1 protein was decreased by genistein or AG556, but not by PP2. These results provide the novel information that epidermal growth factor receptor kinase, but not Src-family kinases, regulates the recombinant cardiac I Ks stably expressed in HEK 293 cells via phosphorylating KCNQ1 protein of the channel. © 2009 Elsevier B.V. All rights reserved.postprin

Human ether-à-go-go gene potassium channels are regulated by EGFR tyrosine kinase

Human ether á-go-go gene potassium channels (hEAG1 or Kv10.1) are expressed in brain and various human cancers and play a role in neuronal excitement and tumor progression. However, the functional regulation of hEAG channels by signal transduction is not fully understood. The present study was therefore designed to investigate whether hEAG1 channels are regulated by protein tyrosine kinases (PTKs) in HEK 293 cells stably expressing hEAG1 gene using whole-cell patch voltage-clamp, immunoprecipitation, Western blot, and mutagenesis approaches. We found that the selective epidermal growth factor receptor (EGFR) kinase inhibitor AG556 (10μM), but not the platelet growth factor receptor (PDGFR) kinase inhibitor AG1295 (10μM) or the Src-family inhibitor PP2 (10μM), can inhibit hEAG1 current, and the inhibitory effect can be reversed by the protein tyrosine phosphatase (PTP) inhibitor orthovanadate. Immunoprecipitation and Western blot analysis revealed that tyrosine phosphorylation level of hEAG1 channels was reduced by AG556, and the reduction was significantly countered by orthovanadate. The hEAG1 mutants Y90A, Y344A and Y485A, but not Y376A and Y479A, exhibited reduced response to AG556. Interestingly, the inhibition effect of AG556 was lost in triple mutant hEAG1 channels at Y90, Y344, and Y485 with alanine. These results demonstrate for the first time that hEAG1 channel activity is regulated by EGFR kinase at the tyrosine residues Tyr 90, Try 344, and Try 485. This effect is likely involved in regulating neuronal activity and/or tumor growth. © 2011 Elsevier B.V.postprin

Kinase inhibit region of SOCS3 attenuates IL6-induced proliferation and astrocytic differentiation of neural stem cells via cross talk between signaling pathways

Aims: Efficiency of neural stem cells (NSCs) therapy for brain injury is restricted by astrogliosis around the damaged region, in which JAK2/STAT3 signaling plays a key role. The SOCS3 that can directly inhibit JAK/STAT3 pathway. Here, we investigated the effects of a fusion peptide that combined kinase inhibitory region (KIR) of SOCS3 and virus trans-activator of transcription (TAT) on biological behavior of cultured NSCs under inflammatory conditions. Methods: NSCs were isolated from embryonic brain of SD rats, TAT-KIR was synthesized, and penetration rate was evaluated by flow cytometry (FACS). CCK8, immunostaining, and FACS were used to detected of TAT-KIR on the proliferation of NSCs. The expressions of GFAP and β tubulin III positive cells induced by IL6 with/without TAT-KIR were examined by immunostaining and Western blotting to observe the NSCs differentiation, and the effect of TAT-KIR on signaling cross talk was observed by Western blotting. Results: Penetration rate of TAT-KIR into primary cultured NSCs was up to 94%. TAT-KIR did not affect the growth and viability of NSCs. It significantly reduced the NSCs proliferation that enhanced by IL-6 stimulation via blocking the cell cycle progression from the G0/G1 to S phase. In addition, TAT-KIR attenuated astrocytic differentiation and kept high level of neuronal differentiation derived from IL-6-induced NSCs. The fate of NSCs differentiation under inflammatory conditions was affected by TAT-KIR, which was associated with synchronous inhibition of STAT3 and AKT, while promoting JNK expression. Conclusion: TAT-KIR mimetic of SOCS3 could be a promising approach for brain repair via regulating the biological behaviors of exogenous NSCs

Circuit dissection of the role of somatostatin in itch and pain

Stimuli that elicit itch are detected by sensory neurons that innervate the skin. This information is processed by the spinal cord; however, the way in which this occurs is still poorly understood. Here we investigated the neuronal pathways for itch neurotransmission, particularly the contribution of the neuropeptide somatostatin. We find that in the periphery, somatostatin is exclusively expressed in Nppb+ neurons, and we demonstrate that Nppb+somatostatin+ cells function as pruriceptors. Employing chemogenetics, pharmacology and cell-specific ablation methods, we demonstrate that somatostatin potentiates itch by inhibiting inhibitory dynorphin neurons, which results in disinhibition of GRPR+ neurons. Furthermore, elimination of somatostatin from primary afferents and/or from spinal interneurons demonstrates differential involvement of the peptide released from these sources in itch and pain. Our results define the neural circuit underlying somatostatin-induced itch and characterize a contrasting antinociceptive role for the peptide

Molecular cloning and preliminary function study of iron responsive element binding protein 1 gene from cypermethrin-resistant Culex pipiens pallens

<p>Abstract</p> <p>Background</p> <p>Insecticide resistance jeopardizes the control of mosquito populations and mosquito-borne disease control, which creates a major public health concern. Two-dimensional electrophoresis identified one protein segment with high sequence homology to part of <it>Aedes aegypti </it>iron-responsive element binding protein (IRE-BP).</p> <p>Method</p> <p>RT-PCR and RACE (rapid amplification of cDNA end) were used to clone a cDNA encoding full length IRE-BP 1. Real-time quantitative RT-PCR was used to evaluate the transcriptional level changes in the Cr-IRE strain <it>Aedes aegypti </it>compared to the susceptible strain of <it>Cx. pipiens pallens</it>. The expression profile of the gene was established in the mosquito life cycle. Methyl tritiated thymidine (³H-TdR) was used to observe the cypermethrin resistance changes in C6/36 cells containing the stably transfected IRE-BP 1 gene of <it>Cx. pipiens pallens</it>.</p> <p>Results</p> <p>The complete sequence of iron responsive element binding protein 1 (IRE-BP 1) has been cloned from the cypermethrin-resistant strain of <it>Culex pipiens pallens </it>(Cr-IRE strain). Quantitative RT-PCR analysis indicated that the IRE-BP 1 transcription level was 6.7 times higher in the Cr-IRE strain than in the susceptible strain of 4th instar larvae. The IRE-BP 1 expression was also found to be consistently higher throughout the life cycle of the Cr-IRE strain. A protein of predicted size 109.4 kDa has been detected by Western blotting in IRE-BP 1-transfected mosquito C6/36 cells. These IRE-BP 1-transfected cells also showed enhanced cypermethrin resistance compared to null-transfected or plasmid vector-transfected cells as determined by ³H-TdR incorporation.</p> <p>Conclusion</p> <p>IRE-BP 1 is expressed at higher levels in the Cr-IRE strain, and may confer some insecticide resistance in <it>Cx. pipiens pallens</it>.</p

Staff and patient experiences of decision-making about continuous observation in psychiatric hospitals

Purpose: Continuous observation of psychiatric inpatients aims to protect those who pose an acute risk of harm to self or others, but involves intrusive privacy restrictions. Initiating, conducting and ending continuous observation requires complex decision-making about keeping patients safe whilst protecting their privacy. There is little published guidance about how to balance privacy and safety concerns, and how staff and patients negotiate this in practice is unknown. To inform best practice, the present study, therefore, aimed to understand how staff and patients experience negotiating the balance between privacy and safety during decision-making about continuous observation. Methods: Thematic analysis of qualitative interviews with thirty-one inpatient psychiatric staff and twenty-eight inpatients. Results: Most patients struggled with the lack of privacy but valued feeling safe during continuous observation. Staff and patients linked good decision-making to using continuous observation for short periods and taking positive risks, understanding and collaborating with the patient, and working together as a supportive staff team. Poor decision-making was linked to insufficient consideration of observation’s iatrogenic potential, insufficient collaboration with patients, and the stressful impact on staff of conducting observations and managing risk. Conclusions: Best practice in decision-making about continuous observation may be facilitated by making decisions in collaboration with patients, and by staff supporting each-other in positive risk-taking. To achieve truly patient-centred decision-making, decisions about observation should not be influenced by staff’s own stress levels. To address the negative impact of staff stress on decision-making, it may be helpful to improve staff training, education and support structures

Wearable high-performance pressure sensors based on three-dimensional electrospun conductive nanofibers

Polymer-based pressure sensors play a key role in realizing lightweight and inexpensive wearable devices for healthcare and environmental monitoring systems. Here, conductive core/shell polymer nanofibers composed of poly (vinylidene fluoride-co-hexafluoropropene) (PVDF-HFP)/poly(3,4-ethylenedioxythiophene) (PEDOT) are fabricated using three-dimensional (3D) electrospinning and vapor deposition polymerization methods, and the resulting sponge-like 3D membranes are used to create piezoresistive-type pressure sensors. Interestingly, the PEDOT shell consists of well-dispersed spherical bumps, leading to the formation of a hierarchical conductive surface that enhances the sensitivity to external pressure. The sponge-like 3D mats exhibit a much higher pressure sensitivity than the conventional electrospun 2D mats due to their enhanced porosity and pressure-tunable contact area. Furthermore, large-area, wireless, 16 x 10 multiarray pressure sensors for the spatiotemporal mapping of multiple pressure points and wearable bands for monitoring blood pressure have been fabricated from these 3D mats. To the best of our knowledge, this is the first report of the fabrication of electrospun 3D membranes with nanoscopically engineered fibers that can detect changes in external pressure with high sensitivity. The developed method opens a new route to the mass production of polymer-based pressure sensors with high mechanical durability, which creates additional possibilities for the development of human-machine interfaces.11Ysciescopu

Unicentric mixed variant castleman disease associated with intrabronchial plasmacytoma.

Castleman disease (CD), described as a heterogeneous lymphoproliferative disorder, can be divided into different subtypes according to clinical appearance (unicentric and multicentric form) and histopathological features (hyaline vascular, plasma cell, mixed type, human herpesvirus 8-associated and multicentric not otherwise specified). Unicentric CD is known to be usually of the hyaline vascular variant, plasma cell and mixed type of this form are quite uncommon. Malignancies are mainly associated with the multicentric form. We report a rare case of unicentric mixed variant CD evolving into intrabronchial, extramedullary plasmacytoma.Intrabronchial mass with consequential obstruction of the left main bronchus, left lung atelectasis and mediastinal lymphadenomegaly was detected by chest CT in our patient suffering from cough and hemoptysis. Pulmonectomy was performed, histopathological and immunhistochemical analysis of lymph nodes revealed mixed type of CD with interfollicular monotypic plasma cell proliferation. The intrabronchial mass consisted of monotypic plasma cells confirming plasmacytoma. Systemic involvement was not confirmed by further tests.Although malignancies more often present in multicentric CD that usually belongs to the plasma cell subtype, this case confirms the neoplastic potential of the rarest, unicentric mixed variant of CD.Virtual slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2872096831190851