Whether building organs or maintaining healthful adult tissues, cells use biochemical and mechanical tips from their environment to make important decisions, such as becoming a neuron, a skin cell or a heart cell. Scientists with UC Santa Barbara have developed a powerful new technique that will reveals for the first time the mechanical environment that cells understand in living tissues — their natural, unaltered three-dimensional habitat.
“Knowing how tissues respond to mechanical cues in the living embryo and how these people physically sculpt tissues and organs in the 3D area will transform the way we think about developmental processes, inch said Otger Campà s, a professor in the Section of Mechanical Engineering at UCSB and senior writer on the paper that reports this novel technique within Nature Methods . “Importantly, this understanding will help us better understand healthy tissue homeostasis as well as the wide range of diseases that involve abnormal tissue mechanics, specifically cancer. ”
The growth and development of a residing organism is a choreography of cellular movements and actions that follow internal genetic guidelines and specific biochemical plus mechanical signals. All these events conspire over time to create a number of complex forms and textures that make our tissues plus organs functional. Scientists have focused for decades on the part of biochemical cues in embryonic development, Campà t said, because no techniques existed to measure the mechanised cues that cells are exposed to during the formation of tissue and organs.
“We know that the mechanised environment of cells is important, ” explained Campà t, who holds the UCSB Mellichamp Endowed Chair within Systems Biology and Bioengineering. “Growing stem cells upon synthetic surfaces with different levels of compliance showed that originate cells would become a different cell type depending exclusively on the mechanical environment they perceive. If you put wanting stem cells on a substrate like Jell-O — by mechanical means similar to brain tissue — they turn into neurons. When you put them on something harder, similar to embryonic bone fragments, they turn into bone-like cells. ”
So far, scientists did not have a method for studying the mechanical features of native cellular environments — that is, cells encircled by other cells and matrix scaffolds within residing tissues. As a consequence, it was not possible to know how cells react to the mechanical cues they perceive as they build cells and organs.
“The technique we created allows the measurement of the mechanical properties such as tightness and viscosity within living tissues, ” said writer Friedhelm Serwane, who is currently at the Max Planck Start for Intelligent Systems in Stuttgart, Germany. “This is definitely exciting because important cell functions are controlled simply by those mechanical properties. If we can measure the mechanical attributes within living organisms now we might be able to understand better just how this relationship between mechanics and biology works. inch
Key to this method are tiny magnetically responsive droplets inserted between cells in the developing embryo. When exposed to a magnetic field, these magnetic tiny droplets deform, pushing on nearby cells. By carefully managing the composition of the droplets and the strength of the magnet field, the forces applied by the droplet can be managed, and the response of the surrounding tissue reveals its mechanised characteristics as well as the cues that cells are exposed to as the cells grows. This technique is complementary to a previous methodology produced by Campà s and colleagues that revealed the allows that cells apply to each other in growing tissues.
The scientists applied their new technique to research how the vertebrate body axis is mechanically built. Making use of embryos of zebrafish, which was selected for its rapid advancement and optical transparency, they could show that the mechanical attributes of the tissue change along the body axis, facilitating recognized of the body at its posterior end. Inserting magnet droplets at different locations in the tissue, and producing forces by applying a magnetic field to the droplets, the particular researchers showed that the tissue behaves like a fluid whilst growing, with similar mechanical characteristics as thick darling. The data showed that the tissue is more fluid at the posterior end where it was growing, and becomes less liquid far from the growing region.
“It is comparable to glass-blowing, ” said Campà s. “The tissue much more fluid in growing regions and ‘fixes’ its form by becoming less fluid where it does not need to increase. ”
The scientists’ findings have broad implications in the effort to understand how organs are toned into their shapes and how cells respond to their native mechanised environment both in healthy tissues and during disease. The particular Campà s lab is studying several of these questions, which includes how limbs are built and how mechanical changes in cancers affect the behavior of malignant cells and the growth from the tumor.
Materials provided by University of California – Santa Barbara . Original written by Sonia Fernandez. Note: Articles may be edited for style and length.