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 mitochondria during sepsis in various studies. The role of the mitochondria in sepsis is still inconsistent, despite the many studies conducted. 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 and 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 that get 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, not to mention all the animal models used. Fourth, there is diversity within the mitochondria since it possesses its own set of DNA. Finally, the way oxygen consumption is measure is different.

LESSON COMMENTS: A good article for students to learn about mitochondrial function beyond the basic glycolysis-TCA cycle-ETC system. Teachers could also tie the contradictory evidence and the various experimental methods to teaching students about the importance of a control and consistency in the scientific method.

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.