{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T02:03:20Z","timestamp":1772244200202,"version":"3.50.1"},"posted":{"date-parts":[[2026,2,27]]},"group-title":"Biology and Life Sciences","reference-count":0,"publisher":"MDPI AG","license":[{"start":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T00:00:00Z","timestamp":1772150400000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,2,20]]},"abstract":"<jats:p>Background\/ Objectives: Phytosterols (Ps), plant-derived bioactive compounds not synthesized by the organism, reduce intestinal cholesterol absorption and, when consumed regularly, lower plasma cholesterol concentrations. MicroRNAs (miRNAs) are small non-coding RNAs that regulate post-transcriptional gene expression and participate in various physiological processes, with their dysregulation being associated with diseases. Among them, miR-33a\/b, intronic microRNAs (miRNAs) located within the sterol regulatory element-binding protein 2 and 1 genes (SREBP-2 and -1), respectively, have recently been shown to regulate lipid homeostasis in concert with their host genes. However, there is a scarcity of studies on the interaction between Ps and miRNAs. We aimed at evaluating the effects of Ps on the expression of miR-33a\/b and genes related to cholesterol transport (ABCA1, ABCG1, NPC1L1, ABCG5, ABCG8) in hepatocytes (Hep-G2), enterocytes (Caco-2), and macrophages (THP-1). Methods: Hep-G2, Caco-2, and THP-1 cells were treated with \u03b2-sitosterol (Ps), cholesterol (Ch), Ps+Ch (25 \u00b5M\/24 h), or culture medium only (control). Total RNA, including miRNAs, was extracted with TRIzol\u2122 and the expression of miRNAs was analyzed by RT-qPCR using the Poly-A tailing protocol and the 2-\u0394\u0394Ct method. Comparisons were made using ANOVA or Kruskal-Wallis (p &amp;lt; 0.05). Results: Ps increased miR-33a\/b in Hep-G2 (p &amp;lt;0.001), while Ch reduced their expression. In THP-1, Ch elevated miR-33a\/b (p &amp;lt;0.005) and Ps reduced them, with a concomitant increase in ABCA1. In Caco-2, no significant changes were observed. Conclusions: Ps distinctly modulate miR-33a\/b in hepatocytes and macrophages, suggesting a role in cholesterol homeostasis and reverse cholesterol transport. These findings reinforce the cardioprotective potential of phytosterols.<\/jats:p>","DOI":"10.20944\/preprints202602.1355.v1","type":"posted-content","created":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T01:08:33Z","timestamp":1772240913000},"source":"Crossref","is-referenced-by-count":0,"title":["Effects of Phytosterol Supplementation on miR-33a\/b Expression in Human Cell Lines"],"prefix":"10.20944","author":[{"given":"Celma M.","family":"Martins","sequence":"first","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0009-0002-6874-0657","authenticated-orcid":false,"given":"Val\u00e9ria A.","family":"Machado","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0365-6916","authenticated-orcid":false,"given":"Margarida G.","family":"Carvalho","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6339-8699","authenticated-orcid":false,"given":"Antonio M.","family":"Figueiredo-Neto","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8340-7302","authenticated-orcid":false,"given":"Attilio","family":"Galhardo","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9911-4598","authenticated-orcid":false,"given":"Francisco A.H.","family":"Fonseca","sequence":"additional","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5738-2623","authenticated-orcid":false,"given":"Maria C.","family":"Izar","sequence":"additional","affiliation":[]}],"member":"1968","container-title":[],"original-title":[],"deposited":{"date-parts":[[2026,2,28]],"date-time":"2026-02-28T01:08:56Z","timestamp":1772240936000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.preprints.org\/manuscript\/202602.1355\/v1"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,27]]},"references-count":0,"URL":"https:\/\/doi.org\/10.20944\/preprints202602.1355.v1","relation":{},"subject":[],"published":{"date-parts":[[2026,2,27]]},"subtype":"preprint"}}