Why does COVID-19 only affect some organs, not others?

In severe cases COVID-19 can cause damage outside the lungs and in other organs such as the heart, liver, kidneys and parts of the neurological system. In addition to these specific sets of organs, however, the virus seems to be affected.

Ernesto Estrada, of the University of Zaragoza and Agencia Aragonesa para la Investigación Foundation in Spain, intended to discover a statement on how it is possible for this damage to propagate selectively instead of affecting the whole body. He discusses his findings in the journal Chaos.

To enter human cells, the coronavirus requires interaction with an abundant protein called angiotensin-converting enzyme 2.

“This receptor is ubiquitous in most human organs, as when the virus circulates in the body, it can also enter other organs and affect them,” Estrada said. “However, the virus affects some organs selectively and not all, as expected from these potential mechanisms.”

Once in a human cell, the proteins of the virus interact with those in the body, allowing it to cultivate its effects. COVID-19 only damages a subset of organs, signaling to Estrada that there must be another path for its transmission. To discover a plausible route, he considered the displacements of proteins that occurred in the lungs and how they interact with proteins in other organs.

“For two proteins to find each other and form an interaction complex, they must move in the cell in a subdiffusive manner,” Estrada said.

He described this subdiffusive motion as resembling a drink driver walking on a volume street. The club presents obstacles for the drunkard, eliminates repression and makes it difficult to reach the destination.

Similarly, proteins in a cell show multiple perfect obstacles that they must overcome in order to interact. Adding to the complexity of the process, some proteins exist within the same cell as organ, but others do not.

With this in mind, Estrada developed a mathematical model by which he could find a group of 59 proteins in the lungs that act as the primary activators that affect other human organs. A chain of interactions, beginning with this set, triggers changes in proteins on the line, ultimately affecting their health.

“Preparation of some of these proteins in the lungs with existing drugs will prevent the perturbation of the proteins expressed in organs other than the lungs, and prevent multiorgan failure, which in many cases results in the death of the patient leads, “said Estrada.

How the affected proteins travel between organs remains an open question that Estrada dedicates to future studies.