A study online in Genome Biology this week describes a dozen microRNAs with blood expression patterns that may help in diagnosing Alzheimer's disease. By sequencing small RNAs in blood samples from four dozen individuals with Alzheimer's disease and 22 unaffected individuals, researchers from Germany and the US identified more than 100 differentially expressed miRNAs in the affected group. From there, they narrowed in on a 12-miRNA signature that accurately distinguished between blood samples from individuals with or without Alzheimer's disease in follow-up experiments. The expression profile also showed promise for detecting a handful of other neurological conditions and differentiating them from Alzheimer's disease. For more on the study, check out a related news story from our sister publication GenomeWeb Daily News.
An international team led by investigators at the St. Laurent Institute used new and existing RNA sequence data to track down 2,147 very long intergenic, non-coding RNAs, or vlincRNAs, in human cells. A subset of the vlincRNAs showed tissue-specific expression, they found, and many of those had promoters falling in retroviral repeat sequences in the genome. Though the vlincRNAs were detected in human cells from both normal and cancerous tissues, the expression of those with endogenous retroviral promoters tends to get bumped up in malignant cells and/or cells with a high degree of pluripotency, prompting the study's authors to argue that "very long RNAs that traverse our genome may regulate gene expression in the nucleus, spiking in early development, and capable of re-activation in the malignant cellular state."
A UK-led team takes a look the gene expression shifts that occur in certain tissue types with age. The researchers did array-based gene expression profiling on abdominal skin and adipose tissue samples from 856 female twins between the ages of 39- and 85-years-old, as well as lymphoblastoid cell lines generated for the women. The most pronounced age-related expression differences turned up in skin tissue. There, the team found nearly 1,700 genes with expression profiles that differed with age, compared to 188 in the adipose tissue samples. A dozen of the genes highlighted in the skin samples and three from the adipose samples also showed age-related expression differences in post-mortem brain that the investigators tested subsequently.