Detection of ER stress in vivo by Raman spectroscopy

The endoplasmic reticulum (ER) is an organelle in which most membrane and secretory proteins are synthesized. If these proteins are not folded correctly, unfolded proteins accumulate in the ER lumen, causing a cellular situation known as ER stress. Recently, many studies on the relationship between ER stress and diseases have been reported. Thus, studies of ER stress in vivo should yield information that is useful in pathology. Model mice have been developed as a powerful tool to visualize ER stress in vivo, but this approach depends on transgenic technology. Here, we report on a method of detecting ER stress in vivo by Raman spectroscopy. Our experiments revealed that two specific Raman bands were reduced in both cultured cells and animal tissues in an ER stress dependent manner. This suggests that Raman spectroscopy could be a useful tool to detect ER stress in vivo without transgenic technology.

Research highlights
► ER stress was able to detect by Raman spectroscopy in cultured cells.
► ER stress was able to detect by Raman spectroscopy in animal tissues.
► ER stress was detected as reduction of specific Raman bands by Raman spectroscopy.
► We could detect ER stress in animal tissues without transgenic technology.
► ER stress was able to detect low-invasively in animal tissues by Raman spectroscopy.