Life Science, M&E 3: Cellular Respiration (HS), Non-NGSS Articles, S&F 1: Cells (MS), S&F 2: Cell Function (MS), Structure and Function

Mitochondrial respiration during sepsis

Variability of mitochondrial respiration in relation to sepsis-induced multiple organ dysfunction

SUMMARY: This is an article review on how oxygen is used by the mitochondrion during sepsis. The role of mitochondria play during sepsis is still inconsistent, despite the various studies that have been done. There are three hypotheses for mitochondrial dysfunction.

1. Mitochondria are “victims” of decreased oxygen levels caused elsewhere in the body and thus, this decrease in oxygen would decrease ATP production.

2. Mitochondria are damaged by DAMPs (danger-associated molecular patterns).

3. Lack of oxygen causes mitochondria to go into hibernation mode.

None of these hypotheses have good supporting evidence. There’s also a lot of contradictory evidence. The study then goes on to give a few reasons for the contradictory evidence. First, there is variation within the human population when it comes to who is more vulnerable to sepsis (male, female, diabetic, etc). Second, studies in the laboratory use different animals. Third, there are different models of sepsis. Some models use blood from cancer patients, some use in vitro cells, and animal models use different types of animals. Fourth, there is diversity within the mitochondria since it possesses its own set of DNA. Finally, oxygen consumption is measured in different ways.

LESSON COMMENTS: A good article for students to learn about mitochondrial function beyond the basic glycolysis-Krebs cycle-ETC system. Teachers could also tie the contradictory evidence and the various experimental methods to the importance of a control and the need for controlled variables.

Kohoutová, M & Dejmek, Jiri & Tuma, Zdenek & Kuncová, Jitka. (2018). Variability of mitochondrial respiration in relation to sepsis-induced multiple organ dysfunction. Physiological research. 67. S577-S592.