“You are a machine” – this sentence does not only apply to muscle-bound people, but to each and every one of us. In addition to the mechanical analogy, our body can also be compared to a complex electrical machine. This is because it consists of various control centers and individual parts that are connected by circuits.
Every molecule, every cell, every organ can be part of several circuits and thereby take on different functions – be a transmitter or receiver, or function as a transmitter.
Circuits within the cell
As you already read in the article Hallmarks of Health 1 – Intact barriers As you could read, each cell is its own reaction chamber with several additional compartments. Each of these individual chambers and their contents is part of one or more circuits, but at the same time is also connected to circuits outside the cell.
Within a cell, for example, AMP has several functions. AMP stands for adenosine monophosphate and is a building block of RNARNA is the working copy of our DNA, which provides the instructions for building proteins. AMP is also a product that is produced during the breakdown of ATP (the universal energy currency of our cells). If a cell needs a lot of energy - i.e. ATP - the molecule is broken down and AMP is released. Consequently, a high AMP level in the cell indicates high energy consumption.
The high concentration of AMP can, as an indicator of a low energy level, shut down energy-intensive processes in the cell in order to save energy. This happens through the AMP-dependent kinase (AMPK)As the name suggests, this kinase - an enzyme that changes the structure of other proteins and thus their function - is dependent on the molecule AMP. In the case of high AMP levels, the kinase is activated and changes the structure of enzymes that are responsible for very energy-intensive or catabolic processes. So if the cell is already consuming a lot of energy, this circuit reduces energy consumption in parts of the cells.
Similar to AMP, there are many circuits or feedback loops in the cell that control and influence the processes there. But functions outside of a separate cell space can also be influenced by cell products.
Switching from inside to outside
In case of damage in the cell, it either via intracellular pathways Apoptosis (i.e. programmed cell death) or the cell issues a “destruction command” to the outsideThis is a classic example from the field of immunology and is used, for example, in the case of damage caused by an infection. If the cell has been “attacked”, so to speak, it can theoretically happen that the pathogen influences the cell in such a way that the pathogen spreads further. This is very typical in the case of viral infections.
To prevent this, cells have developed the DAMPS or PAMPS mechanism. STEAM is the abbreviation for damage-associated pattern (Damage-associated pattern) – also called Alarmin. PAMP stands for pathogen-associated pattern (Pathogen associated pattern). These can be different molecules that are released in the event of cell damage and thus activate the immune system - this is the "destruction signal". The corresponding cell is then destroyed by cells of the immune system. This is controlled by different molecules that are also part of the circuit. This communication from cells to the outside and from cells to each other is important. But without commands from outside to the cell, nothing works. Let's look at this third communication path.
Circuits from outside to inside
We now know that cells act on their own and react to commands that they receive from other cells. But they also react to external, non-organic commands. A good example is light, which can activate some circuits. Light activates the production of melanin in our skin cells and shrinks the pupils in the eye so that less light hits the retina. Our sleep rhythm is also influenced by light (more on this in the next article on rhythmic oscillation). There are specialised sensor cells in our body that react to external influences such as light, pH value, temperature or pressure. As part of a circuit, they receive external influences via receptors and translate them into the language of the body, i.e. at the molecular level. Other cells then react to them. But not only the sensor cells, but every cell in our body reacts to external influences.
Organs and systemic units
All parts of our body are connected to each other at the cellular level. But organs and parts of different body units also communicate within themselves and with each other. And what is the most important control center of our body? - That's right, the brain, or more precisely our central nervous system, which also includes the spinal cord. Here, signals are not only sent, but also received, processed and forwarded.
Meta-connections: organisms within the organism
Other organisms also play a major role in the functionality of our body. The intestinal flora (microbiota) is always in the spotlight of various studies on our health. It has a significant impact on us and consists of billions of bacteria and other microorganisms. The microbiota is said to have an impact on allergies, the immune system and our mental health, among other things. It is therefore not surprising that this cog is also important for the overall circuit of the body. The intestinal microbiome can therefore be the reason for both health and illness.
The Domino Problem of Circuits
The integration of all these circuits and their individual gears is essential for a functioning overall machinery and in the event of malfunctions at individual points, our body has effective repair mechanisms. Nevertheless, the complex interconnection also leads to Disease rarely affects only individual areas, but manifests itself in various symptoms through numerous connections.
As you can see from the examples, all of these and all other functional chains within our body, in the organs and in and between the cells, are essential for a well-functioning organism as a whole and therefore for health. The body's overall machinery consists of a breathtaking number of individual circuits and individual gears that turn. However, as soon as individual important chains are lost or no longer function properly, this can have a chain reaction that affects other processes and thus endangers our overall health.
Some of these circuits are dependent on products of the body, some are dependent on external factors. Others are subject to a regularity within their dependence. In this case we speak of oscillation. To this oscillating rhythms, which include our sleep-wake rhythm and the menstrual cycle, we will discuss in the next article of the Hallmarks of Health received.
Sources
Literature:
López-Otín, Carlos, and Guido Kroemer. “Hallmarks of health.”Cell184.1 (2021): 33-63.https://pubmed.ncbi.nlm.nih.gov/33340459/
Images:
The images were purchased under license from Shutterstock or Canva and are marked accordingly.
