Nanoscale Chromatin Response to Mechanical Stimulus

ongoing

Cells respond to physical stimuli from their environment, drastically changing their chromatin organization. Direct nuclear mechanotransduction affects cell behavior, but this mechanism is still not fully understood. This unsolved link is due to the difficulty of finding tools to generate precise mechanical signals and observe changes in chromatin at the nanoscale level. NanoCHROMS aims to understand the effect of nuclear mechanotransduction on nuclear architecture. We aim to characterize the mechanism driving localized chromatin structure changes in response to direct physical stimuli, and how these changes relate to cellular state. NanoCHROMS will exploit two novel and powerful technologies, Nanofabrication and Single Molecule Localization Microscopy (SMLM). For that, we will use nanopillars as nanomechanical actuators. By culturing somatic, stem and cancer cells in a fabricated nanopillar surface, purposely designed to be SMLM-compatible, we can exert a precise, controlled, and replicable force in the nucleus. Using SMLM, we can unveil higher order chromatin folding with nanometric precision, obtaining positional information of DNA and nucleosome packaging, directly related to cell function. By using SMLM in cells growing on nanopillared surfaces, we can establish the changes of chromatin in direct relation to the physical point of application of the stimulus at the nanoscale. Finally, using sequence-specific imaging approaches (Oligopaints) we will study the nuclear positioning and compaction of genes whose expression is drastically affected by mechanotransduction. NanoCHROMS will contribute to understanding the mechanisms driving expression changes, maintenance of stemness and oncogenesis by mechanostimulus, being a steppingstone in projects working in the interface between cell biology and nanomaterials science. Finally, NanoCHROMS will develop a systematic and quantitative method to evaluate the effect of different nanostructures on nuclear architecture.