Synthesis of Anilino‐monoindolylmaleimides as Potent and Selective PKCβ Inhibitors.

Tanaka, Masahiro; Sagawa, Shoichi; Hoshi, Jun‐ichi; Shimona, Fumito; Matsuda, Isamu; Sakoda, Kenji; Sasase, Tomohiko; Shindo, Masanori; Inaba, Takashi

doi:10.1002/chin.200505104

Cited by 7 publications

(9 citation statements)

References 1 publication

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“…7). As 30 nM LY379196 had no effect in our studies, and because higher concentrations of this agent yield nonspecific effects (29), we performed follow-up experiments using a commercially available compound (50 nM indolylmaleimide1) that also selectively inhibits PKC␤ (IC 50 ϭ 5-21 nM) (54). These experiments were performed more than 1 yr after the LY379196 investigation and utilized a new luminometer (same model) and freshly purchased lucigenin.…”

Section: Effects Of Isoform-specific Pkc Inhibition On O 2 •ϫ Productmentioning

confidence: 99%

PKC-dependent superoxide production by the renal medullary thick ascending limb from diabetic rats

Yang¹,

Lane

Pollock

et al. 2009

American Journal of Physiology-Renal Physiology

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Type 1 diabetes (T1D) is a state of oxidative stress accompanied by PKC activation in many tissues. The primary site of O2*- production by the normal rat kidney is the medullary thick ascending limb (mTAL). We hypothesized that T1D increases O2*- production by the mTAL through a PKC-dependent mechanism involving increased expression and translocation of one or more PKC isoforms. mTAL suspensions were prepared from rats with streptozotocin-induced T1D (STZ mTALs) and from normal or sham rats (normal/sham mTALs). O2*- production by STZ mTALs was fivefold higher than normal/sham mTALs (P < 0.05). PMA (30 min) mimicked the effect of T1D on O2*- production. Exposure to calphostin C or chelerythrine (PKC inhibitors), Gö6976 (PKCalpha/beta inhibitor), or rottlerin (PKCdelta inhibitor) decreased O2*- production to <20% of untreated baseline in both normal/sham and STZ mTALs. PKCbeta inhibitors had no effect. PKC activity was increased in STZ mTALs (P < 0.05 vs. normal/sham mTALs) and was unaltered by antioxidant exposure (tempol). PKCalpha protein levels were increased by 70% in STZ mTALs, with a approximately 30% increase in the fraction associated with the membrane (both P < 0.05 vs. sham). PKCbeta protein levels were elevated by 29% in STZ mTALs (P < 0.05 vs. sham) with no change in the membrane-bound fraction. Neither PKCdelta protein levels nor its membrane-bound fraction differed between groups. Thus STZ mTALs display PKC activation, upregulation of PKCalpha and PKCbeta protein levels, increased PKCalpha translocation to the membrane, and accelerated O2*- production that is eradicated by inhibition of PKCalpha or PKCdelta (but not PKCbeta). We conclude that increased PKCalpha expression and activity are primarily responsible for PKC-dependent O2*- production by the mTAL during T1D.

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Section: Effects Of Isoform-specific Pkc Inhibition On O 2 •ϫ Productmentioning

confidence: 99%

PKC-dependent superoxide production by the renal medullary thick ascending limb from diabetic rats

Yang¹,

Lane

Pollock

et al. 2009

American Journal of Physiology-Renal Physiology

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show abstract

“…11A, bar 2). In order to narrow down the possible isoforms of PKC, an inhibitor specific to the b I and b II isoforms was utilized (Tanaka et al, 2004) (note: according to the manufacturer, this inhibitor also shows some specificity towards PKC a isoform, IC 50 ¼ 331 nM). Inhibition of the selected PKC isoforms resulted in comparable results as the broad spectrum inhibitor, Bis-1 (Fig.…”

Section: Effect Of Pkc Activation/inhibition On Electrical Coupling Amentioning

confidence: 99%

Lipopolysaccharide plus hypoxia and reoxygenation synergistically reduce electrical coupling between microvascular endothelial cells by dephosphorylating Connexin40

Bolon

Peng

Kidder

et al. 2008

Journal Cellular Physiology

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We showed that lipopolysaccharide (LPS) or hypoxia and reoxygenation (H/R) decreases electrical coupling between microvascular endothelial cells by targeting the gap junction protein connexin40 (Cx40), tyrosine kinase-, ERK1/2-, and PKA-dependently. Since LPS can compromise microvascular blood flow, resulting in micro-regional H/R, the concurrent LPS + H/R could reduce coupling to a much greater extent than LPS or H/R alone. We examined this possibility in a model of cultured microvascular endothelial cells (mouse skeletal muscle origin) in terms of electrical coupling and the phosphorylation status of Cx40. To assess coupling, we measured the spread of electrical current injected into the cell monolayer and computed the intercellular resistance as an inversed measure of coupling. In wild type cells, but not in Cx40 null cells, concurrent LPS + H/R synergistically increased resistance by approximately 270%, well above the level observed for LPS or H/R alone. Cx37 and Cx43 protein expression did not differ between Cx40 null and wild type cells. LPS + H/R increased resistance PKA- and PKC-dependently. By immunoprecipitating Cx40, we found that LPS + H/R reduced serine phosphorylation to a much greater degree than that observed for LPS or H/R alone. Further, PKA-specific, but not PKC-specific serine phosphorylation of Cx40 was also significantly reduced following LPS + H/R. This reduction was prevented by tyrosine kinase and MEK1/2 inhibition, by PKA activation, and mimicked in control cells by PKA inhibition. We conclude that LPS + H/R initiates tyrosine kinase- and ERK1/2-sensitive signaling that synergistically reduces inter-endothelial electrical coupling by dephosphorylating PKA-specific serine residues of Cx40.

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“…Antibodies used in the present study include the following: mouse anti-PKC␣ antibody, mouse anti-PKC␤ antibody (BD Biosciences, San Jose, Calif), mouse anti-VCAM-1 (C3P4), mouse anti-ICAM-1 (P2A4) (Chemicon International, Temecula, Calif), rabbit anti-NF-B p65 antibody, rabbit anti-IB␣ antibody, rabbit anti-␤-actin antibody (Santa Cruz Biotechnology, Inc, Santa Cruz, Calif), and goat anti-apoCIII antibody (Academy Biomedical). 17 as well as NF-B inhibitor cell permeable peptide SN50 18 and its control scrambled peptide were purchased from Calbiochem (San Diego, Calif).…”

Section: Cell Culture and Reagentsmentioning

confidence: 99%

Apolipoprotein CIII Induces Expression of Vascular Cell Adhesion Molecule-1 in Vascular Endothelial Cells and Increases Adhesion of Monocytic Cells

et al. 2006

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Background-Activation of vascular endothelial cells (ECs) plays an important role in atherogenesis and plaque instability. Lipoproteins containing apolipoprotein CIII (apoCIII) predict coronary heart disease (CHD). We recently reported that apoCIII has a proinflammatory effect on human monocytes. In this study, we looked for a direct effect of apoCIII on EC expression of adhesion molecules, leading to monocytic cell adhesion. Methods and Results-Treatment of ECs with apoCIII or apoCIII-rich VLDL caused human monocytic THP-1 cells to adhere to them under static condition or under laminar sheer stress (1.0 dyne/cm 2 ). ApoCIII increased EC expression of vascular cell adhesion molecule-1 (VCAM-1) protein and intercellular cell adhesion molecule-1 (ICAM-1) protein (4.9Ϯ1.5-fold and 1.4Ϯ0.5-fold versus control, respectively). Furthermore, apoCIII remarkably increased membranebound protein kinase C (PKC) ␤ in ECs, indicating activation. A selective inhibitor of PKC␤ prevented the rise in VCAM-1 and THP-1 cell adhesion to ECs. Moreover, exposure of ECs to apoCIII induced nuclear factor-B (NF-B) activation. PKC␤ inhibition abolished apoCIII-induced NF-B activation, and NF-B inhibition reduced expression of VCAM-1, each resulting in reduced THP-1 cell adhesion. ApoCIII-rich VLDL also activated PKC␤ and NF-B in ECs and increased expression of VCAM-1. Pretreatment of ApoCIII-rich VLDL with anti-apoCIII neutralizing antibody abolished its effect on PKC␤ activation. Conclusions-Our findings provide the first evidence that apoCIII increases VCAM-1 and ICAM-1 expression in ECs by activating PKC␤ and NF-B, suggesting a novel mechanism for EC activation induced by dyslipidemia. Therefore, apoCIII-rich VLDL may contribute directly to atherogenesis by activating ECs and recruiting monocytes to them.

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Synthesis of Anilino‐monoindolylmaleimides as Potent and Selective PKCβ Inhibitors.

Cited by 7 publications

References 1 publication

PKC-dependent superoxide production by the renal medullary thick ascending limb from diabetic rats

PKC-dependent superoxide production by the renal medullary thick ascending limb from diabetic rats

Lipopolysaccharide plus hypoxia and reoxygenation synergistically reduce electrical coupling between microvascular endothelial cells by dephosphorylating Connexin40

Apolipoprotein CIII Induces Expression of Vascular Cell Adhesion Molecule-1 in Vascular Endothelial Cells and Increases Adhesion of Monocytic Cells

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