{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T05:25:26Z","timestamp":1787030726502,"version":"build-2736575974"},"reference-count":48,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2026,8,16]],"date-time":"2026-08-16T00:00:00Z","timestamp":1786838400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Science and Technology Council","award":["MOST 111-2314-B-303-015-MY3"],"award-info":[{"award-number":["MOST 111-2314-B-303-015-MY3"]}]},{"name":"National Science and Technology Council","award":["NSTC 114-2314-B-303-015-MY3"],"award-info":[{"award-number":["NSTC 114-2314-B-303-015-MY3"]}]},{"award":["MOST 111-2314-B-303-015-MY3"],"award-info":[{"award-number":["MOST 111-2314-B-303-015-MY3"]}],"id":[{"id":"https:\/\/ror.org\/02kv4zf79","id-type":"ROR","asserted-by":"publisher"}]},{"award":["NSTC 114-2314-B-303-015-MY3"],"award-info":[{"award-number":["NSTC 114-2314-B-303-015-MY3"]}],"id":[{"id":"https:\/\/ror.org\/02kv4zf79","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int. J. Mol. Sci.","IJMS"],"abstract":"<jats:p>Vascular calcification (VC) is a major complication of chronic kidney disease (CKD) that is strongly associated with cardiovascular mortality. While indoxyl sulfate (IS), a protein-bound uremic toxin, has been implicated in the progression of VC, the underlying molecular mechanisms remain unclear. We investigated the procalcific effects of IS using a two-step nephrectomy-induced CKD mouse model and cultured vascular smooth muscle cells. In vivo, progressive renal impairment was associated with elevated circulating IS levels and enhanced VC. In vitro, IS dose- and time-dependently induced calcium deposition, increased reactive oxygen species (ROS) production, and upregulated osteogenic markers, including runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2), and osteocalcin (OCN), whereas N-acetyl-L-cysteine (NAC) partially attenuated IS-induced ROS accumulation and cell injury. Mechanistically, IS exposure activated extracellular signal-regulated kinase (ERK) and Wnt\/\u03b2-catenin signaling while suppressing nuclear factor erythroid 2-related factor 2 (Nrf2)-related antioxidant responses, as reflected by reductions in the phosphorylated Nrf2 (pNrf2) to total Nrf2 and heme oxygenase-1 (HO-1) expression. Pharmacological inhibition of ERK and Wnt\/\u03b2-catenin signaling attenuated IS-induced osteogenic responses. These findings indicate that IS promotes VC in association with increased oxidative stress, activation of ERK and Wnt\/\u03b2-catenin signaling, and impaired Nrf2-related antioxidant defense. These integrated findings provide mechanistic insight into IS-associated VC and highlight oxidative stress-related signaling networks as potential therapeutic targets in CKD.<\/jats:p>","DOI":"10.3390\/ijms27167314","type":"journal-article","created":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T12:01:26Z","timestamp":1786968086000},"page":"7314","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Indoxyl Sulfate Promotes Vascular Calcification in Association with Oxidative Stress and Activation of ERK and Wnt\/\u03b2-Catenin Signaling Pathways"],"prefix":"10.3390","volume":"27","author":[{"given":"Yi-Cheng","family":"Wang","sequence":"first","affiliation":[{"name":"Division of Nephrology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97004, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3021-0979","authenticated-orcid":false,"given":"I-Min","family":"Su","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi 62247, Taiwan"},{"name":"School of Medicine, Tzu Chi University, Hualien 97004, Taiwan"},{"name":"Institute of Medical Sciences, Tzu Chi University, Hualien 97004, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chung-Jen","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Nursing, Tzu Chi University, Hualien 97004, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tsung-Jui","family":"Wu","sequence":"additional","affiliation":[{"name":"Institute of Medical Sciences, Tzu Chi University, Hualien 97004, Taiwan"},{"name":"Division of Nephrology, Department of Medicine, Hualien Armed Forces General Hospital, National Defense Medical Center, Hualien 97144, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9364-4558","authenticated-orcid":false,"given":"Bang-Gee","family":"Hsu","sequence":"additional","affiliation":[{"name":"Division of Nephrology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97004, Taiwan"},{"name":"School of Medicine, Tzu Chi University, Hualien 97004, Taiwan"},{"name":"Institute of Medical Sciences, Tzu Chi University, Hualien 97004, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e31464","DOI":"10.1002\/jcp.31464","article-title":"Advances in the mechanisms of vascular calcification in chronic kidney disease","volume":"240","author":"Wang","year":"2025","journal-title":"J. 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