Cholesterol regulation and channel protein degradation in BK-HEK 293 cells with co-expressing β1-subunit.

<p><b>A</b>. BK channel current recorded with the voltage protocol (inset) in cells treated with bafilomycin A1, lactacystin, MβCD-cholesterol, MβCD-cholesterol plus bafilomycin A1, or MβCD-cholesterol plus lactacystin. <b>B</b>. BK channel current at +60 mV in cells treated with bafilomycin A1 (n = 16, <i>P</i> = NS vs. control), lactacystin (n = 15, <i>P</i> = NS vs. control), MβCD-cholesterol (MβCD-chol, n = 19, **<i>P</i><0.01 vs. control), MβCD-cholesterol plus bafilomycin A1 (n = 14, ^##<i>P</i><0.01 vs. MβCD-cholesterol), or MβCD-cholesterol plus lactacystin (n = 18, ^##<i>P</i><0.01 vs. MβCD-cholesterol). <b>C</b>. Western immunoblots showing KCa1.1 protein in cells treated with bafilomycin A1, lactacystin, MβCD-cholesterol, MβCD-cholesterol plus bafilomycin A1, or MβCD-cholesterol plus lactacystin. <b>D</b>. Mean percentage values of KCa1.1 protein in cells treated with bafilomycin A1, lactacystin, MβCD-cholesterol, MβCD-cholesterol plus bafilomycin A1, or MβCD-cholesterol plus lactacystin (n = 6, **<i>P</i><0.01 vs. control; ^##<i>P</i><0.01 vs. MβCD-cholesterol).</p

Effects of LDL on BK channel current in BK-HEK 293 cells.

<p><b>A</b>. Voltage-dependent BK current recorded with voltage protocol as shown in the inset in cells treated with LDL (75 µg/mL) or LDL plus MβCD treatment. <b>B</b>. <i>I-V</i> relationships of BK current in control, LDL or LDL plus MβCD treatment (n = 25, *<i>P</i><0.05; **<i>P</i><0.01 vs. control). <b>C</b>. Percentage values compared to control of BK current at +60 mV in control (n = 25), with LDL (n = 32, **<i>P</i><0.01 vs. control), and LDL plus MβCD treatment (n = 10, ^##<i>P</i><0.01 vs. LDL alone). <b>D</b>. Activation variables calculated with <i>I-V</i> relationships of the channel current in panel <b>B</b> were fitted to a Boltzmann function. <b>E</b>. Western immunoblots showing KCa1.1 protein and the auxiliary β1-subunit protein in cells treated with LDL or LDL plus MβCD. <b>F</b>. Mean percentage values of KCa1.1 protein and the auxiliary β1-subunit protein in cells with LDL or LDL plus MβCD (n = 6-9, **<i>P</i><0.01 vs. control, ^#<i>P</i><0.05 vs. LDL alone).</p

Cholesterol effect on KCa1.1 current.

<p><b>A</b>. Voltage-dependent KCa1.1 current recorded in hKCa1.1-HEK 293 cells with the voltage protocol (<i>inset</i>) in cells treated with cholesterol depletion (MβCD) or cholesterol enrichment (MβCD-cholesterol). <b>B</b>. <i>I-V</i> relationships of hKCa1.1 current in control (n = 19), cholesterol depletion (n = 16, *<i>P</i><0.05 or **<i>P</i><0.01 vs. control at 0 to +60 mV) or cholesterol-enrichment (n = 11, <i>P</i> = NS vs. control). <b>C</b>. Percentage values of hKCa1.1 current at +60 mV in control (n = 16), cholesterol depletion (n = 19, **<i>P</i><0.01 vs. control) or cholesterol enrichment (n = 11, ^##<i>P</i><0.01 vs. MβCD alone). <b>D</b>. Single channel activity of hKCa1.1 channels recorded in cell-attached mode at +60 mV in cells treated with 5 mM MβCD or MβCD-cholesterol. The labels C, O₁ and O₂ indicate the close level, 1^st and 2^nd opening levels of the channel. <b>E</b>. Histograms of open probability of hKCa1.1 single channels in cells treated without (control) or with cholesterol depletion (MβCD). <b>F</b>. Mean values of open probability of hKCa1.1 channels in control (n = 8), MβCD (n = 6), and MβCD-cholesterol (n = 6, *<i>P</i><0.05 vs. control). <b>G</b>. Conductance of hKCa1.1 channels in control, MβCD, and MβCD-cholesterol (n = 6–8, <i>P</i> = NS vs. control).</p

Single channel activity of BK channels.

<p><b>A</b>. Single channel activity of BK channels recorded with cell-attached mode at +60 mV in cells treated with 5 mM MβCD or MβCD-cholesterol. The labels C, O₁ and O₂ indicate the close level, 1^st and 2^nd opening levels of the channel. <b>B</b>. Histograms of open probability of BK single channels in cells treated without (control) or with cholesterol enrichment (MβCD-cholesterol). <b>C</b>. Mean values of open probability of BK channels in control (n = 7), MβCD (n = 6), and MβCD-cholesterol (n = 7, **<i>P</i><0.01 vs. control). <b>D</b>. Conductance of BK channels in control, MβCD, and MβCD-cholesterol (n = 6–7, <i>P</i> = NS vs. control).</p

Effect of cholesterol on KCa1.1 protein in cultured human coronary artery smooth muscle cells.

<p>A. BK current was recorded in a representative human coronary artery smooth muscle cell with the voltage protocol shown in the inset, and the current was inhibited by 1 µM paxilline. B. BK current was recorded in cells treated without/with MβCD or MβCD-cholesterol. C. Mean values of BK current at +80 mV in cells treated with MβCD (n = 5) or MβCD-cholesterol (n = 5, **<i>P</i><0.01 vs. control, n = 6). D. Western immunoblots showing KCa1.1 protein in human coronary artery smooth muscle cells treated with cholesterol depletion (MβCD), cholesterol enrichment (MβCD-cholesterol), LDL, or LDL plus MβCD. E. Mean percentage values of BK protein in cells with different treatments (<i>n</i> = 4–6, **<i>P</i><0.01 vs. control, ^#<i>P</i><0.05 vs. LDL alone).</p

Protein expression of BK channels in BK-HEK 293 cells with co-expressing auxiliary β1-subunit.

<p><b>A</b>. Western immunoblots showing KCa1.1 protein and the auxiliary β1-subunit protein in cells treated with cholesterol depletion (MβCD) or cholesterol enrichment (MβCD-cholesterol). <b>B</b>. Mean percentage values of KCa1.1 protein and the β1-subunit protein in cells with different treatments (n = 6–9, **<i>P</i><0.01 vs. control). <b>C</b>. Immunocytochemistry showing membrane expression of KCa1.1 protein in cells treated with cholesterol depletion (MβCD) or cholesterol enrichment (MβCD-cholesterol). Cholesterol enrichment induced a reduction of membrane expression of BK channels.</p

Effects of silencing KCa1.1 or Kir2.1 on cell migration in human cardiac c-kit⁺ progenitor cells.

<p><b>(A)</b>: Images of human cardiac c-kit⁺ progenitor cells with wound-healing migration assay in confluent cells transfected with control siRNA, KCa1.1 siRNA or Kir2.1 siRNA (40 nM for each group). <b>(B)</b>: Images of migrated human cardiac c-kit⁺ progenitor cells to the lower membrane in cells transfected with control siRNA, KCa1.1 siRNA or Kir2.1 siRNA (40 nM for each group). <b>(C)</b>: Mean values of ratio of migrated cells in cells transfected with control siRNA, KCa1.1 siRNA or Kir2.1 siRNA (40 nM for each group, n = 5 for each group, *<i>P</i><0.05, **<i>P</i><0.01 vs. control siRNA).</p

Taylor impact test for ductile porous materials - Part 1: Theory

Taylor tests have been commonly employed to determine dynamic yield stress of solids at a high strain rate. In this paper, the original Taylor model is extended in order to provide a theoretical basis for testing ductile porous materials. The key difference between solids and porous materials in this respect is that porous materials are compressible and their density changes with the compressive strain. Calculations have been made for porous materials with a relative density that is a linear function of compressive strain. The final length of the projectile after impact, L1/L, is plotted against parameter ?0U2/Y (see Fig. 9) and this plot is used in a Taylor test to determine the dynamic yield stress. The mean strain rate of the test can be estimated from Eqs. (21) or (22). In a companion paper (Int J Impact Eng), experiments for dynamic yield stress of porous materials will be reported based on the present theoretical analysis

Effects of specific siRNA molecules on expression of ion channel genes and proteins in human cardiac c-kit⁺ progenitor cells.

<p><b>(A)</b>: PCR images and relative level of KCa1.1 mRNA in cells treated with lipofectamine 2000 (Lipo), control siRNA, or KCa1.1 siRNA. <b>(B)</b>: Western blots and relative level of KCa1.1 protein in cell treated with lipofectamine 2000, control siRNA, or KCa1.1 siRNA. <b>(C)</b>: PCR images and relative level of Kir2.1 mRNA in cells treated with lipofectamine 2000, control siRNA, or Kir2.1 siRNA. <b>(D)</b>: Western blots and relative level of Kir2.1 protein in cell treated with lipofectamine 2000, control siRNA, or Kir2.1 siRNA (n = 6 for each group, **<i>P</i><0.01 vs. control siRNA).</p

Effects of silencing KCa1.1 or Kir2.1 on cell migration in human cardiac c-kit⁺ progenitor cells.

<p><b>(A)</b>: Images of human cardiac c-kit⁺ progenitor cells with wound-healing migration assay in confluent cells transfected with control siRNA, KCa1.1 siRNA or Kir2.1 siRNA (40 nM for each group). <b>(B)</b>: Images of migrated human cardiac c-kit⁺ progenitor cells to the lower membrane in cells transfected with control siRNA, KCa1.1 siRNA or Kir2.1 siRNA (40 nM for each group). <b>(C)</b>: Mean values of ratio of migrated cells in cells transfected with control siRNA, KCa1.1 siRNA or Kir2.1 siRNA (40 nM for each group, n = 5 for each group, *<i>P</i><0.05, **<i>P</i><0.01 vs. control siRNA).</p