{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,24]],"date-time":"2026-09-24T00:05:34Z","timestamp":1790208334402,"version":"4.1.0"},"reference-count":28,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T00:00:00Z","timestamp":1787529600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Fundamental Research Grant Scheme, Ministry of Higher Education, Malaysia","award":["FRGS\/1\/2025\/SKK10\/UKM\/02\/6"],"award-info":[{"award-number":["FRGS\/1\/2025\/SKK10\/UKM\/02\/6"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Int. J. Mol. Sci.","IJMS"],"abstract":"<jats:p>Diabetes mellitus induces endothelial dysfunction and oxidative stress, contributing to the development of vascular complications. Although metformin exerts well-established vasculoprotective and antioxidant effects, the molecular mechanisms underlying these actions remain incompletely understood. Novel miR-1133 was previously identified as a metformin-responsive putative microRNA (miRNA), and bioinformatic analysis identified PIK3CA as a biologically plausible candidate target for further investigation. This study investigated the functional significance of novel miR-1133 in the antioxidant effects of metformin in hyperglycemia-induced human umbilical vein endothelial cells (HUVECs). HUVECs were exposed to normal glucose (5.5 mmol\/L), hyperglycemia (33.3 mmol\/L), or hyperglycemia supplemented with metformin (10 \u03bcM) for 24 h. Metformin-treated hyperglycemic HUVECs were subsequently transfected with a novel miR-1133 mimic during continued hyperglycemic and metformin exposure. PIK3CA expression and oxidative stress markers, including reactive oxygen species (ROS), superoxide dismutase (SOD), and 8-hydroxy-2\u2032-deoxyguanosine (8-OHdG), were evaluated. Hyperglycemia increased novel miR-1133 expression, whereas metformin reduced its expression. Metformin treatment was associated with increased PIK3CA mRNA and protein expression, reduced ROS and 8-OHdG levels, and increased SOD expression and activity. Novel miR-1133 mimic transfection was associated with reduced PIK3CA expression, increased ROS and 8-OHdG levels, and decreased SOD expression and activity compared with the corresponding transfection control. Collectively, these findings demonstrate that metformin attenuates oxidative stress in hyperglycemia-induced endothelial cells and overall provide the first functional characterization of novel miR-1133. The reciprocal changes in PIK3CA expression and oxidative stress observed following novel miR-1133 mimic transfection suggest that novel miR-1133 may represent a candidate mediator of the endothelial antioxidant responses associated with metformin. Further studies are required to validate the direct interaction between novel miR-1133 and PIK3CA and to elucidate the underlying molecular mechanisms.<\/jats:p>","DOI":"10.3390\/ijms27177556","type":"journal-article","created":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T11:47:19Z","timestamp":1787572039000},"page":"7556","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Functional Characterization of Putative Novel MicroRNA-1133 in the Antioxidant Effects of Metformin in Hyperglycemia-Induced Endothelial Cells"],"prefix":"10.3390","volume":"27","author":[{"given":"Nur Syakirah","family":"Othman","sequence":"first","affiliation":[{"name":"Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1329-0444","authenticated-orcid":false,"given":"Amilia","family":"Aminuddin","sequence":"additional","affiliation":[{"name":"Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia"},{"name":"Cardiovascular and Pulmonary (CardioResp) Research Group, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adila A.","family":"Hamid","sequence":"additional","affiliation":[{"name":"Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia"},{"name":"Cardiovascular and Pulmonary (CardioResp) Research Group, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shahidee Zainal","family":"Abidin","sequence":"additional","affiliation":[{"name":"Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, Kuala Nerus 21030, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Saiful Effendi","family":"Syafruddin","sequence":"additional","affiliation":[{"name":"UKM Medical Molecular Biology Institute (UMBI), Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2735-3274","authenticated-orcid":false,"given":"Mohd Faizal","family":"Ahmad","sequence":"additional","affiliation":[{"name":"Department of Obstetrics and Gynecology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7645-3805","authenticated-orcid":false,"given":"Farah Hanan Fathihah","family":"Jaffar","sequence":"additional","affiliation":[{"name":"Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-5807-4203","authenticated-orcid":false,"given":"Nur Athirah","family":"Othman Basri","sequence":"additional","affiliation":[{"name":"Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia"},{"name":"Faculty of Health Sciences, MAIWP International University, Kuala Lumpur 68100, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8268-3316","authenticated-orcid":false,"given":"Azizah","family":"Ugusman","sequence":"additional","affiliation":[{"name":"Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia"},{"name":"Cardiovascular and Pulmonary (CardioResp) Research Group, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,24]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (2025, November 24). Diabetes. Available online: https:\/\/www.who.int\/news-room\/fact-sheets\/detail\/diabetes."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1038\/s41419-017-0135-z","article-title":"Cellular Death, Reactive Oxygen Species (ROS) and Diabetic Complications Review-Article","volume":"9","author":"Volpe","year":"2018","journal-title":"Cell Death Dis."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"107832","DOI":"10.1016\/j.pharmthera.2021.107832","article-title":"Endothelial Function and Dysfunction: Impact of Sodium-Glucose Cotransporter 2 Inhibitors","volume":"224","author":"Ugusman","year":"2021","journal-title":"Pharmacol. Ther."},{"key":"ref_4","first-page":"e66570","article-title":"Biomarkers of Oxidative Stress and Their Clinical Relevance in Type 2 Diabetes Mellitus Patients: A Systematic Review","volume":"16","author":"S","year":"2024","journal-title":"Cureus"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1038\/s41420-024-02278-8","article-title":"Free Radicals and Their Impact on Health and Antioxidant Defenses: A Review","volume":"11","author":"Chandimali","year":"2025","journal-title":"Cell Death Discov."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Al-Mahayni, S., Ali, M., Khan, M., Jamsheer, F., Moin, A.S.M., and Butler, A.E. (2023). Glycemia-Induced MiRNA Changes: A Review. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms24087488"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Grieco, G.E., Brusco, N., Licata, G., Nigi, L., Formichi, C., Dotta, F., and Sebastiani, G. (2019). Targeting MicroRNAs as a Therapeutic Strategy to Reduce Oxidative Stress in Diabetes. Int. J. Mol. Sci., 20.","DOI":"10.3390\/ijms20246358"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"499","DOI":"10.2478\/jomb-2018-0009","article-title":"Profiles of Circulating MiRNAs Following Metformin Treatment in Patients with Type 2 Diabetes","volume":"37","author":"Demirsoy","year":"2018","journal-title":"J. Med. Biochem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"30870","DOI":"10.1038\/s41598-024-81427-6","article-title":"Metformin-Loaded Nanoparticles Reduce Hyperglycemia-Associated Oxidative Stress and Induce ENOS Phosphorylation in Vascular Endothelial Cells","volume":"14","author":"Mohamed","year":"2024","journal-title":"Sci. Rep."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Goel, S., Singh, R., Singh, V., Singh, H., Kumari, P., Chopra, H., Sharma, R., Nepovimova, E., Valis, M., and Kuca, K. (2022). Metformin: Activation of 5\u2032 AMP-Activated Protein Kinase and Its Emerging Potential beyond Anti-Hyperglycemic Action. Front. Genet., 13.","DOI":"10.3389\/fgene.2022.1022739"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1035","DOI":"10.1007\/s00210-024-03358-3","article-title":"Metformin and the PI3K\/AKT Signaling Pathway: Implications for Cancer, Cardiovascular, and Central Nervous System Diseases","volume":"398","author":"Ashayeri","year":"2025","journal-title":"Naunyn-Schmiedeberg\u2019s Arch. Pharmacol."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Othman, N.S., Aminuddin, A., Zainal Abidin, S., Syafruddin, S.E., Ahmad, M.F., Mohd Mokhtar, N., Kumar, J., Hamid, A.A., and Ugusman, A. (2023). Profiling of Differentially Expressed MicroRNAs in Human Umbilical Vein Endothelial Cells Exposed to Hyperglycemia via RNA Sequencing. Life, 13.","DOI":"10.3390\/life13061296"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"667","DOI":"10.17576\/MH.2025.2002.17","article-title":"Metformin Alters the MicroRNA Profile of High Glucose-Induced Human Umbilical Vein Endothelial Cells","volume":"20","author":"Othman","year":"2025","journal-title":"Med. Health"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"H1744","DOI":"10.1152\/ajpheart.01088.2004","article-title":"Hyperglycemia Alters PI3k and Akt Signaling and Leads to Endothelial Cell Proliferative Dysfunction","volume":"289","author":"Varma","year":"2005","journal-title":"Am. J. Physiol.-Heart Circ. Physiol."},{"key":"ref_15","first-page":"8112","article-title":"PI3K\/AKT Signaling Pathway Plays a Role in Enhancement of ENOS Activity by Recombinant Human Angiotensin Converting Enzyme 2 in Human Umbilical Vein Endothelial Cells","volume":"7","author":"Zhang","year":"2014","journal-title":"Int. J. Clin. Exp. Pathol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"713","DOI":"10.1089\/152308603770380016","article-title":"Redox Regulation of PI3K\/Akt and P53 in Bovine Aortic Endothelial Cells Exposed to Hydrogen Peroxide","volume":"5","author":"Niwa","year":"2003","journal-title":"Antioxid. Redox Signal."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Zhu, L., Chen, Q., and Wang, B. (2026). PI3K\/AKT Signaling Pathway: New Strategies for Treating Atherosclerosis with Plant-Derived Compounds. Front. Pharmacol., 17.","DOI":"10.3389\/fphar.2026.1722493"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Zhao, Y., Qian, Y., and Sun, Z. (2021). Role of PI3K in the Progression and Regression of Atherosclerosis. Front. Pharmacol., 12.","DOI":"10.3389\/fphar.2021.632378"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"381","DOI":"10.1016\/j.cell.2017.04.001","article-title":"AKT\/PKB Signaling: Navigating the Network","volume":"169","author":"Manning","year":"2017","journal-title":"Cell"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1907","DOI":"10.2147\/DDDT.S409373","article-title":"Metformin: A Review of Potential Mechanism and Therapeutic Utility Beyond Diabetes","volume":"17","author":"Dutta","year":"2023","journal-title":"Drug Des. Dev. Ther."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Angelika, B., Iwona, S., Adam, J.K., and Agnieszka, A. (2024). Examining the Clinical Relevance of Metformin as an Antioxidant Intervention. Front. Pharmacol., 15.","DOI":"10.3389\/fphar.2024.1330797"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"775","DOI":"10.1007\/s10787-022-00980-6","article-title":"The Role of AMPK-Dependent Pathways in Cellular and Molecular Mechanisms of Metformin: A New Perspective for Treatment and Prevention of Diseases","volume":"30","author":"Hasanvand","year":"2022","journal-title":"Inflammopharmacology"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"193","DOI":"10.2337\/db16-0915","article-title":"Metformin Suppresses Diabetes-Accelerated Atherosclerosis via the Inhibition of Drp1-Mediated Mitochondrial Fission","volume":"66","author":"Wang","year":"2017","journal-title":"Diabetes"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"829","DOI":"10.1016\/j.metabol.2005.01.029","article-title":"Metformin Decreases Intracellular Production of Reactive Oxygen Species in Aortic Endothelial Cells","volume":"54","author":"Ouslimani","year":"2005","journal-title":"Metabolism"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"970","DOI":"10.14336\/AD.2021.1213","article-title":"Metformin\u2019s Mechanisms in Attenuating Hallmarks of Aging and Age-Related Disease","volume":"13","author":"Cheng","year":"2022","journal-title":"Aging Dis."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Reed, S., Taka, E., Darling-Reed, S., and Soliman, K.F.A. (2025). Neuroprotective Effects of Metformin Through the Modulation of Neuroinflammation and Oxidative Stress. Cells, 14.","DOI":"10.3390\/cells14141064"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"424","DOI":"10.1111\/j.1476-5381.2011.01230.x","article-title":"Metformin Restores Endothelial Function in Aorta of Diabetic Rats","volume":"163","author":"Sena","year":"2011","journal-title":"Br. J. Pharmacol."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Hamid, A.A., Aminuddin, A., Anuar, N.N.M., Mansor, N.I., Ahmad, M.F., Saleh, M.S.M., Mokhtar, M.H., and Ugusman, A. (2022). Persicaria Minor (Huds.) Opiz Prevents In Vitro Atherogenesis by Attenuating Tumor Necrosis Factor-\u03b1-Induced Monocyte Adhesion to Human Umbilical Vein Endothelial Cells. Life, 12.","DOI":"10.3390\/life12101462"}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/17\/7556\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T11:56:34Z","timestamp":1787572594000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/27\/17\/7556"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,24]]},"references-count":28,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["ijms27177556"],"URL":"https:\/\/doi.org\/10.3390\/ijms27177556","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,24]]}}}