MicroRNAs regulate synthesis of the neurotransmitter substance P in human mesenchymal stem cell-derived neuronal cells

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 104; no. 39; pp. 15484 - 15489
• Main Authors: Greco, Steven J, Rameshwar, Pranela
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 25.09.2007; National Acad Sciences
• Subjects: 3' Untranslated Regions; adults; algorithms; Base Sequence; Binding sites; Biological Sciences; Bone marrow; Cell Differentiation; Cell nucleus; Gene expression; genes; Humans; interleukin-1alpha; Interleukin-1alpha - metabolism; luciferase; Mesenchymal stem cells; Mesoderm - cytology; Messenger RNA; MicroRNA; MicroRNAs - metabolism; Models, Biological; Molecular Sequence Data; muscle development; neoplasms; Neurons; Neurons - cytology; Neurons - metabolism; Neurotransmitter Agents - metabolism; Neurotransmitters; non-coding RNA; Protein synthesis; Reverse transcriptase polymerase chain reaction; Ribonucleic acid; RNA; Stem cells; Stem Cells - cytology; Stem Cells - metabolism; substance P; Substance P - metabolism; Tachykinins - metabolism; translation (genetics); Untranslated regions; Up-Regulation
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.0703037104

MicroRNAs (miRNAs) are a class of 19- to 23-nt, small, noncoding RNAs, which bind the 3' UTR of target mRNAs to mediate translational repression in animals. miRNAs have been shown to regulate developmental processes, such as self-renewal of stem cells, neuronal differentiation, myogenesis, and cancer. A functional role of miRNAs in the regulation of neurotransmitter synthesis has yet to be ascribed. We used mesenchymal stem cells (MSCs) as a model to study miRNA-mediated neurotransmitter regulation in developing neuronal cells. MSCs are mesoderm-derived cells, primarily resident in adult bone marrow, which can generate functional neuronal cells. We have previously shown that human MSC-derived neuronal cells express the neurotransmitter gene, Tac1, but do not synthesize the gene's encoded peptide, the neurotransmitter substance P (SP), unless stimulated with the inflammatory mediator IL-1α. These findings suggested a potential role for miRNAs in the regulation of SP synthesis. Here, we report on the miRNA profile of undifferentiated human MSCs and MSC-derived neuronal cells by using miRNA-specific bioarrays. miRNAs that were increased in the neuronal cells and decreased after IL-1α stimulation were analyzed by the miRanda algorithm to predict Tac1 mRNA targets. Putative miR-130a, miR-206, and miR-302a binding sites were predicted within the 3' UTR of Tac1. Target validation using a luciferase reporter system confirmed the miR-130a and miR-206 sites. Specific inhibition of miR-130a and miR-206 in the neuronal cells resulted in SP synthesis and release. The studies provide a different approach in ascribing a new regulatory role for miRNAs in regulating neurotransmitter synthesis.