Cold exposure lowers energy expenditure at the cellular level

The human body is an incredibly complex machine. It is made up of countless moving parts that all must communicate and work in tandem in order for it to maintain its functionality. This complexity, however, does not stop at the organ level. It continues down to the most minuscule levels of the body such as the cells and even the parts that make up the cells, the organelles. These microscopic parts of a cell play a key role in the overall working of all biological organisms. One key organelle that receives lots of attention in the academic community is the mitochondria. Simply put, it is responsible for providing the cell with energy in order for it to operate and do its job. But mitochondria do not operate independently from stimuli. Like all other components of living things, they interpret information from the outside and then adjust their behavior in order to best adapt to it. One key example of this is temperature. For example, it is known that mild cold exposure elevates energy expenditure in mammals. This process is known as adaptive thermogenesis. However, what has not been studied in any particular depth is mitochondrial energy expenditure in relation to adaptive thermogenesis. In a study by Park et al. the effects of cold temperatures on mitochondria activity were analyzed to try and get an understanding of how cells monitor temperatures and what the underlying processes are behind this occurrence.

To do this, Park and his team looked at the interaction of adenosine triphosphate (ATP) and mitochondrial membrane potential (ΔΨ_m) at cold temperatures . By looking at the levels of ΔΨ_m, researchers were able to determine that cold-induced cellular responses include both increased energy production in the form of ATP and energy expenditure via mitochondrial uncoupling and thermogenesis. To arrive at this result, Park and his team needed to closely monitor ΔΨ_m using the fluorescent indicator JC-10™. This indicator is particularly effective in situations like this because of its color variation based on excitation. As ΔΨ_m changes, the color emitted will change from green to green-orange. This allows observers to visibly see ΔΨ_m, which helps produce clearer and more reliable results. Additionally, streamlined protocol allows for minimal hands-on time, which minimizes the risk of cell damage and helps protect the integrity of the results.

The results obtained in this study offer some valuable insights into the inner workings of cells and their organelles. The fact that parts of cells can detect and react to temperature changes independent of neurons hints at their awe-inspiring complexity. When dealing with such small subjects and such delicate results, it is important to trust the materials you are working with. The JC-10™ indicator has a greatly improved signal to background ratio, which helps it produce clear and easily visible results that can then be reliably interpreted. When dealing with such small scales being sure that you are observing the intended subject is essential to producing valuable and viable results.

References

---

1. Seyeon Park, Sohyun Chun, Danuh Kim. Cold exposure lowers energy expenditure at the cellular level Cell Biology International (2013), DOI: 10.1002/cbin.10086