14 research outputs found

    One-Dimensional and Multi-Dimensional Integral Transforms of Buschman–Erdélyi Type with Legendre Functions in Kernels

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    This paper consists of two parts. In the first part we give a brief survey of results on Buschman–Erdélyi operators, which are transmutations for the Bessel singular operator. Main properties and applications of Buschman–Erdélyi operators are outlined. In the second part of the paper we consider multi-dimensional integral transforms of Buschman–Erdélyi type with Legendre functions in kernels. Complete proofs are given in this part, main tools are based on Mellin transform properties and usage of Fox H-functions

    Losartan Decreases p42/44 MAPK Signaling and Preserves LZ+ MYPT1 Expression

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    Heart failure is associated with impairment in nitric oxide (NO) mediated vasodilatation, which has been demonstrated to result from a reduction in the relative expression of the leucine zipper positive (LZ+) isoform of the myosin targeting subunit (MYPT1) of myosin light chain phosphatase. Further, captopril preserves normal LZ+ MYPT1 expression, the sensitivity to cGMP-mediated vasodilatation and modulates the expression of genes in the p42/44 MAPK and p38 MAPK signaling cascades. This study tests whether angiotensin receptor blockade (ARB) with losartan decreases p42/44 MAPK or p38 MAPK signaling and preserves LZ+ MYPT1 expression in a rat infarct model of heart failure. In aortic smooth muscle, p42/44 MAPK activation increases and LZ+ MYPT1 expression falls after LAD ligation. Losartan treatment decreases the activation of p42/44 MAPK to the uninfarcted control level and preserves normal LZ+ MYPT1 expression. The expression and activation of p38 MAPK, however, is low and does not change following LAD ligation or with losartan therapy. These data suggest that either reducing or blocking the effects of circulating angiotensin II, both decreases the activation of the p42/44 MAPK signaling cascade and preserves LZ+ MYPT1 expression. Thus, the ability of ACE-inhibitors and ARBs to modulate the vascular phenotype, to preserve normal flow mediated vasodilatation may explain the beneficial effects of these drugs compared to other forms of afterload reduction in the treatment of heart failure

    The p90 Ribosomal S6 Kinase (RSK) Is a Mediator of Smooth Muscle Contractility

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    <div><p>In the canonical model of smooth muscle (SM) contraction, the contractile force is generated by phosphorylation of the myosin regulatory light chain (RLC<sub>20</sub>) by the myosin light chain kinase (MLCK). Moreover, phosphorylation of the myosin targeting subunit (MYPT1) of the RLC<sub>20</sub> phosphatase (MLCP) by the RhoA-dependent ROCK kinase, inhibits the phosphatase activity and consequently inhibits dephosphorylation of RLC<sub>20</sub> with concomitant increase in contractile force, at constant intracellular [Ca<sup>2+</sup>]. This pathway is referred to as Ca<sup>2+</sup>-sensitization. There is, however, emerging evidence suggesting that additional Ser/Thr kinases may contribute to the regulatory pathways in SM. Here, we report data implicating the p90 ribosomal S6 kinase (RSK) in SM contractility. During both Ca<sup>2+</sup>- and agonist (U46619) induced SM contraction, RSK inhibition by the highly selective compound BI-D1870 (which has no effect on MLCK or ROCK) resulted in significant suppression of contractile force. Furthermore, phosphorylation levels of RLC<sub>20</sub> and MYPT1 were both significantly decreased. Experiments involving the irreversible MLCP inhibitor microcystin-LR, in the absence of Ca<sup>2+</sup>, revealed that the decrease in phosphorylation levels of RLC<sub>20</sub> upon RSK inhibition are not due solely to the increase in the phosphatase activity, but reflect direct or indirect phosphorylation of RLC<sub>20</sub> by RSK. Finally, we show that agonist (U46619) stimulation of SM leads to activation of extracellular signal-regulated kinases ERK1/2 and PDK1, consistent with a canonical activation cascade for RSK. Thus, we demonstrate a novel and important physiological function of the p90 ribosomal S6 kinase, which to date has been typically associated with the regulation of gene expression.</p> </div

    IL-17A produced by αβ T cells drives airway hyper-responsiveness in mice and enhances mouse and human airway smooth muscle contraction

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    Emerging evidence suggests that the T(H)17 subset of αβ T cells contributes to the development of allergic asthma. In this study we found that mice lacking αvβ8 on dendritic cells failed to generate T(H)17 cells in the lung and were protected from AHR in response to house dust mite and ovalbumin sensitization and challenge. Because loss of T(H)17 cells inhibited airway narrowing without obvious effects on airway inflammation or epithelial morphology, we examined the direct effects of T(H)17 cytokines on mouse and human airway smooth muscle function. IL-17A enhanced contractile force generation through a NF-κB/RhoA/ROCK2 signaling cascade. Mice lacking integrin αvβ8 on dendritic cells showed impaired activation of this pathway after OVA sensitization and challenge, and the diminished contraction of tracheal rings from these mice was reversed by IL-17A. These data indicate that IL-17A produced by T(H)17 cells contributes to allergen-induced AHR through direct effects on airway smooth muscle
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