AUTHOR=Palihaderu Palihaderu Arachchige Dineth Supasan , Mendis Balapuwaduge Isuru Layan Madusanka , Premarathne Jayasekara Mudiyanselage Krishanthi Jayarukshi Kumari , Dias Wajjakkara Kankanamlage Ruwin , Yeap Swee Keong , Ho Wan Yong , Dissanayake Arosha Sampath , Rajapakse Iyanthimala Harshini , Karunanayake Panduka , Senarath Upul , Satharasinghe Dilan Amila TITLE=Identification of stable reference genes and differential miRNA expression in Sri Lankan type 2 diabetes mellitus patients: a cross-sectional study JOURNAL=Frontiers in Endocrinology VOLUME=Volume 16 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2025.1554827 DOI=10.3389/fendo.2025.1554827 ISSN=1664-2392 ABSTRACT=IntroductionType 2 Diabetes mellitus is a major global health concern. MicroRNA plays an important role in regulating pancreatic beta cells as well as peripheral insulin signaling. This study aimed to identify reference microRNA s in type 2 Diabetes mellitus plasma and validate two target microRNAs among a Sri Lankan population with type 2 diabetes mellitus.MethodsThis is a cross-sectional experiment. A total of fifty-three (N = 53) non-hemolyzed plasma samples from individuals with type 2 diabetes mellitus were selected to evaluate stability, in comparison to thirty-eight (N = 38) normoglycemic non-hemolyzed plasma samples. Initially, the stability of four candidate reference microRNAs (hsa-miR-16-5p, hsa-miR-425-5p, hsa-miR-191-5p, and hsa-miR-22-5p) was assessed. Stability was analyzed using the geNorm and BestKeeper algorithms. The relative expression changes of hsa-miR-29a-3p and hsa-miR-375-3p in the plasma of the same samples were evaluated using the validated reference microRNAs. The selected regulatory microRNAs were directly linked with type 2 diabetes mellitus pathogenesis and proved to be upregulated in type 2 diabetes mellitus plasma and serum.Results and discussionThe expressions of miR-16-5p and miR-191-5p were not stable between the two groups, miR-22-5p and miR-425-5p levels were found to be stable. A significant upregulation of hsa-miR-29a-3p and hsa-miR-375-3p was observed in type 2 diabetes mellitus patients compared to normoglycemic individuals (p ≤ 0.05). This was the first study to claim hsa-miR-425-5p and hsa-miR-22-5p as stably expressed reference microRNAs in type 2 diabetes mellitus patients. Sri Lankan type 2 diabetic patients also had increased hsa-miR-29a-3p and hsa-miR-375-3p levels. However, large and well-matched sample studies were suggested to ensure that these microRNAs can be used as type 2 diabetes diagnostic markers in Sri Lanka.