A ton of time and effort has been spent recently to detail how the external environment can shape our epigenome, but now Peter Jones and company at USC show that we shouldn’t underestimate the power of our internal environment. In a new published report, the USC team found that the extracellular cues taken from the surrounding tissue environment not only shapes how a cell will develop, but as a consequence can also be involved in a number of diseases.
The precise role of tissue environment (post-development) in humans remains unclear due to the limiting ethical nature of such studies. However, by using a clever isogenic human bladder model the resarchers were able to examine the epigenetic state of intestinal cells both before and after the surgical construction of an artificial bladder (which they coined a neobladder).
Here’s what their subsequent analysis using bisulfite arrays revealed:
- In the neobladder, the intestinal (epithelial) cells lose their carefully orchestrated tissue specific epigenetic landscape, and begin to take their hints from being in a bladder environment.
- The epigenetic changes (from intestine to bladder tissue) move in a time-dependent fashion and the clock starts ticking once they are exposed to the bladder setting.
- The new dynamics shape the rates for both de novo methylation of intestine specific enhancers, and rate of demethylation in non-intestine specific transcribed regions.
The authors claim that their “…study is the first to quantify the effect of environmental cues on the human epigenome and show that the local tissue environment directly modulates DNA methylation patterns in normal differentiated cells in vivo,” They also note that the implications are profound, suggesting that “the dynamic resetting of DNA methylome in the neobladder not only implicates local environmental cues in the shaping and maintenance of the epigenome, but also illustrates an unexpected cross-talk between the epigenome and cellular environment.”
Get more cellular advice from Genome Research, February 2014