{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T14:36:19Z","timestamp":1791902179818,"version":"4.3.4"},"reference-count":0,"publisher":"S. Karger AG","issue":"5","license":[{"start":{"date-parts":[[2015,1,1]],"date-time":"2015-01-01T00:00:00Z","timestamp":1420070400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"},{"start":{"date-parts":[[2015,1,1]],"date-time":"2015-01-01T00:00:00Z","timestamp":1420070400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Kidney Blood Press Res"],"published-print":{"date-parts":[[2015]]},"abstract":"<b><i>Background\/Aims: <\/i><\/b>Excessive phosphate concentrations trigger vascular calcification, an active process promoted by osteoinduction of vascular smooth muscle cells (VSMCs) with increased expression and activity of transcription factor RUNX2 (Core-binding factor \u03b11, CBFA1), alkaline phosphatase (ALPL), TGF\u00df1, transcription factor NFAT5, and NFAT5-sensitive transcription factor SOX9. The osteoinductive signaling and vascular calcification of hyperphosphatemic klotho-hypomorphic mice could be reversed by treatment with NH<sub>4<\/sub>Cl, effects involving decrease of TGF\u00df1 and inhibition of NFAT5-dependent osteoinductive signaling. Known effects of NH<sub>4<\/sub>Cl include alkalinization of acidic cellular compartments. The present study explored whether osteo-\/chondrogenic signaling could be influenced by alkalinization of acidic cellular compartments following inhibition of the vacuolar H<sup>+<\/sup> ATPase with bafilomycin A1 or following dissipation of the pH gradient across the membranes of acidic cellular compartments with methylamine. <b><i>Methods: <\/i><\/b>Primary human aortic smooth muscle cells (HAoSMCs) were treated with high phosphate to trigger osteo-\/chondrogenic signaling and calcification in the absence or presence of bafilomycin A1 or methylamine. Calcium content was determined using a QuantiChrom Calcium assay, ALP activity by a colorimetric assay and transcript levels by quantitative RT-PCR. <b><i>Results: <\/i><\/b>High phosphate increased significantly the calcium deposition, <i>CBFA1<\/i> and <i>ALPL<\/i> mRNA expression as well as alkaline phosphatase activity in HAoSMCs, all effects ameliorated by both, bafilomycin A1 and methylamine. High phosphate further significantly up-regulated the mRNA levels of <i>TGFB1, NFAT5<\/i> and <i>SOX9,<\/i> effects significantly blunted by additional treatment with bafilomycin A1 or methylamine. Treatment of HAoSMCs with human TGF\u00df1 protein or high phosphate up-regulated <i>NFAT5, SOX9, CBFA1<\/i> and <i>ALPL<\/i> mRNA expression to similarly high levels which could not be further increased by combined treatment with high phosphate and TGF\u00df1. Bafilomycin A1 failed to reverse the osteo-\/chondrogenic signaling triggered by high phosphate together with TGF\u00df1. <b><i>Conclusions: <\/i><\/b>Inhibition of the vacuolar H<sup>+<\/sup> ATPase or dissipation of the pH gradient across the membranes of acidic cellular compartments both disrupt osteo-\/chondrogenic signaling and calcium deposition in VSMCs, observations supporting the hypothesis that vascular calcification requires acidic cellular compartments.<\/jats:p>","DOI":"10.1159\/000368524","type":"journal-article","created":{"date-parts":[[2015,9,29]],"date-time":"2015-09-29T21:01:28Z","timestamp":1443560488000},"page":"490-499","source":"Crossref","is-referenced-by-count":37,"title":["Inhibition of Phosphate-Induced Vascular Smooth Muscle Cell Osteo-\/Chondrogenic Signaling and Calcification by Bafilomycin A1 and Methylamine"],"prefix":"10.1159","volume":"40","author":[{"given":"Ioana","family":"Alesutan","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katharina","family":"Musculus","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tatsiana","family":"Castor","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kousi","family":"Alzoubi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jakob","family":"Voelkl","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Florian","family":"Lang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"127","published-online":{"date-parts":[[2015,9,30]]},"container-title":["Kidney and Blood Pressure Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/368524","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/368524","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/368524","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,4,23]],"date-time":"2025-04-23T17:50:51Z","timestamp":1745430651000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000368524"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015]]},"references-count":0,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2015,10,1]]},"published-print":{"date-parts":[[2015,10,29]]}},"URL":"https:\/\/doi.org\/10.1159\/000368524","archive":["Portico"],"relation":{},"ISSN":["1420-4096","1423-0143"],"issn-type":[{"value":"1420-4096","type":"print"},{"value":"1423-0143","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015]]}}}