microRNA of the Month: microRNA 125

microRNA of the Week Month – microRNA 125

MicroRNA-125 is a member of a group of microRNAs that are ubiquitously expressed in all tissues and as such, has wide ranging function.  It has been found to play important roles in some of the most devastating illnesses: cancer, neurological disorders, and cardiovascular disease.

Astrogliosis, the rapid proliferation of astrocytes, is associated with chronic neurodegenerative diseases including Alzheimer’s disease and Down’s syndrome.  Levels of the brain enriched microRNA-125b are up-regulated in Alzheimer’s disease and Down’s syndrome brain tissues as well as astrogliosis induced normal human astrocytes. These and other studies suggest that microRNA-125b, which has multiple mRNA targets in the brain, may contribute to neurodegenerative brain disease.^1,2

MicroRNA expression analysis in hepatoblastoma (the most common malignancies of the liver occurring in children aged 15 years or younger) found a group of microRNAs, including  microRNA-125a, to be upregulated. Unsupervised clustering of the microarray expression data showed that these microRNA profiles could distinguish tumor from nontumor tissues, suggesting that these microRNAs could represent valid markers for the classification of pediatric liver tumors.³

 Atherosclerosis, a chronic inflammatory disease of the arterial wall, has enormous epidemiological relevance. It occurs when circulating macrophages take up oxidized low density lipoprotein (oxLDL), which leads to their conversion into foam cells, which in turn secrete proinflammatory factors and eventually form the lipid core of plaques.  MicroRNA-125a-5p was found to mediate lipid uptake and to decrease the secretion of some inflammatory factors in oxLDL-stimulated macrophages, suggesting that it may play a protective role against the development of atherosclerosis.⁴

1. Pogue AI, Cui JG, Li YY, Zhao Y, Culicchia F, Lukiw WJ. (2010) Micro RNA-125b (miRNA-125b) function in astrogliosis and glial cell proliferation. Neurosci Lett [Epub ahead of print]. [abstract]
2. Sethi P, Lukiw WJ.  (2009) Micro-RNA abundance and stability in human brain: specific alterations in Alzheimer’s disease temporal lobe neocortex.  Neurosci Lett 459(2), 100-04.  [abstract]
3. Magrelli A, Azzalin G, Salvatore M, Viganotti M, Tosto F, Colombo T, Devito R, Di Masi A, Antoccia A, Lorenzetti S, Maranghi F, Mantovani A, Tanzarella C, Macino G, Taruscio D. (2009) Altered microRNA Expression Patterns in Hepatoblastoma Patients. Transl Oncol 2(3), 157-63.  [abstract]
4. Ting Chen1, Zhouqing Huang1, Liansheng Wang1, Yue Wang1, Feizhen Wu2, Shu Meng1, Changqian Wang. (2009) MicroRNA-125a-5p partly regulates the inflammatory response, lipid uptake, and ORP9 expression inoxLDL-stimulated monocyte/macrophages.  Cardiovascular Research 83(1), 131-39.  [abstract]