Ion channels in the regulation of autophagy

<p>Autophagy is a cellular process in which the cell degrades and recycles its own constituents. Given the crucial role of autophagy in physiology, deregulation of autophagic machinery is associated with various diseases. Hence, a thorough understanding of autophagy regulatory mechanisms is crucially important for the elaboration of efficient treatments for different diseases. Recently, ion channels, mediating ion fluxes across cellular membranes, have emerged as important regulators of both basal and induced autophagy. However, the mechanisms by which specific ion channels regulate autophagy are still poorly understood, thus underscoring the need for further research in this field. Here we discuss the involvement of major types of ion channels in autophagy regulation.</p

The effects of 1,25-dihydroxyvitamin D3 on androgen-independent cell lines.

<p><b>A</b>, <b>B</b>, The effects of 1,25-dihydroxyvitamin D3 on androgen receptor-deficient DU-145 cell line in both 2 and 10% FCS-containing RPMI medium (<b>A</b> and <b>B</b>, respectively), * - P<0.05 (as compared to control), n = 3. <b>C, D</b>, The effects of 1,25-dihydroxyvitamin D3 on androgen-insensitive LNCaP C4-2 cell line in both 2 and 10% FCS-containing RPMI medium (<b>C</b> and <b>D</b>, respectively), * - P<0.05 (as compared to control), n = 3. <b>E</b>, the relative expression levels of TRPV6 channel in DU-145 cells treated with 100 µM 1,25-dihydroxyvitamin D3 for 3 days in 2 and 10% FCS-containing RPMI medium, * - P<0.05 (as compared to control), n = 3. <b>F</b>, the expression of TRPV6 channel induced by 100 nM 1,25-dihydroxyvitamin D3 for 3 days in LNCaP cells in steroid-deprived RPMI medium (LNCaP-ST), n = 3.</p

Primers and siRNA.

<p>Primers and siRNA.</p

The effects of 1,25-dihydroxyvitamin D3 on proliferation and apoptosis resistance of LNCaP cells are mediated via TRPV6 channel.

<p><b>A</b>, LNCaP cells proliferation in 2% FCS-containing RPMI medium treated with 1,25-dihydroxyvitamin D3 (100 nM, applied at D1), siRNA-TRPV6 (siTRPV6, 80 nM, transfected at D0), the combined treatment of 1,25-dihydroxyvitamin D3 and siTRPV6 specified above, and siRNA-AR (siAR, 80 nM, transfected at D0) as a positive control. * - P<0.05, ** - P<0.01, as compared to control, n = 4; <b>B</b>, a cell cycle assay of LNCaP cells (incubated with 2% FCS-containing RPMI medium) for the same conditions as in MTS assay (<b>A</b>) (D3 equals 100 nM 1,25-dihydroxyvitamin D3), carried out by flow cytometry of the cells stained with propidium iodide. * - P<0.05, ** - P<0.01, § - P<0.05 vs. Vitamin D3; n = 3. <b>C</b>, a western-blotting of proliferating cell nuclear antigen (PCNA) in the conditions indicated above as compared to β-actin. <b>D</b>, an apoptosis assay carried out by flow cytometry as a subG1 population of LNCaP cells cultured in 2% FCS-containing RPMI medium stained with propidium iodide. * - P<0.01 vs. control; n = 3.</p