New labeling method for "exosomes"

Our cells are constantly communicating, and scientists have developed an effective way to find out the information they send in protein-filled biological suitcases called exosomes

These spherical exosomes reside in the inner membrane of the cell, but eventually go out into another cell, transporting macromolecules like proteins, which are the basic components of the human body, drivers of biological activity, and the RNA

"It's an ongoing process," says Dr.

It is thought that in the early stages of exosome formation, the cargo was loaded through the precursor nucleosome near the cell membrane, and it worked much like filling it

Currently, the main way to study exosome content is to first detach the exosomes out of context, which is a rather laborious process that can produce inconsistent results

The MCG research group developed a more efficient way to study only exosome content and studied the location

Their labeling system includes a variant of APEX, ascorbate peroxidase, which fuses

Kwon's research focused on kidney damage, and they used their system to show that oxidative stress (oxidative stress is a byproduct of oxygen use, which in a disease state is excessive and destructive) alters the cargo content of exosomes made by kidney cells and is found

"It turns out that by looking at exosomes in the urine or blood, as well as what's going on inside them, we can tell if the cells are injured or healthy,"

The first time they used this labeling system was in cultured live kidney cells

The scientific team says this labeling system could also help track changes in exosome levels over time, as well as the potential response

Exosomes play a key role in cellular communication, both between cells of the same type and with

While a postdoc at the University of California San Francisco, Kwon grew renal tubules in a Petri dish that returned important nutrients to the bloodstream and eliminated unwanted substances from the urine, and he found evidence that exosomes play a key role in genetic dynamics there, which got him interested

He calls the exosome focus "reverse science," in which most people observe how cells change, while he and a growing number of colleagues look at the envelopes that cells emit to understand their function

Journal of Extracellular Vesicles

Article Title

Ascorbate peroxidase-mediated in situ labelling of proteins in secreted exosomes