Non-Protein-Coding RNA Instability in the Human Postmortem Brain

A majority of the human genome codes for genes that do not produce proteins. Many of these long non-coding RNA (lncRNA) transcripts have evolved at a faster rate than genes that code for proteins, have critical regulatory and structural roles, and have important roles in higher-level brain functioning and diseases. We have shown selective time and cell-type stability of RNA transcripts in human brain during the postmortem interval. Here, we have extended these studies to examine the stability of lncRNAs in a simulated human postmortem interval. We found that lncRNA stability is variable and cell-type specific. While some lncRNAs are stable for up to 24 hours, those expressed in neurons decline rapidly and those expressed in glial cells such as astrocytes and microglia increase dramatically during this same time interval. The lncRNAs are less stable than protein-coding RNAs, and microRNAs were highly unstable in the simulated postmortem interval. Knowing the stability of human brain protein-coding and non-coding genes in the postmortem interval is critical to interpret studies of all human brain disorders ranging from Alzheimer's disease to schizophrenia.