Polio - Quorum Sensing - Stem Cell

Poliomyelitis and Post-polio Syndrome
Polio is a naked, single-strand RNA-containing virus from the Picornoviridae family, one of the smallest viruses. The virus is spread through the fecal-oral route and is incubated for 7-14 days. It replicates on the tonsils of the throat and in the small intestines. It may also go to the lymph nodes of the neck and ileum, to the blood to cause viremia or to the central nervous system. Once it gets into the central nervous system, it may replicate in the motor neurons causing death of the motor neurons. The remaining motor neurons sprout new terminal axons that can innervate orphaned muscle cells to form a large mass of motor unit so that there is muscle activity. Most individuals who experience this will suffer from paralysis, which cause muscle weakness especially in the legs. Post-polio syndrome occurs in about a quarter of the individuals that had polio when they were a child. It is due to the failure of the over-sized motor units that was formed during the time the neurons innervated the orphaned muscle cells.

Is there a way to prevent post-polio syndrome from occurring?

Quorum Sensing
Quorum sensing is a two-component signaling system in which bacteria sense and respond to changes in the environment. It is a communication network between bacteria by detecting environmental cues such as oxygen levels, nutrients, osmotic concentrations, capsule formation, pH, motility, etc. Bacteria are able to secrete signaling molecules that creates gene expressions and activate certain genes. They use quorum sensing to coordinate certain physiological activities such as biofilm formation, toxin production, virulence factors and motility and many more. Bacteria communicate with each other by releasing molecules called autoinducers into the environment that binds to a receptor that was able to detect the signaling molecule, which then activates gene expression.

How can quorum sensing be useful when developing vaccines or treatments?

Stem cells
Stem cells are undifferentiated cells which convert to specialized cells that are useful mainly for medical treatments in replacing diseased or damaged tissue. They have the ability to grow and transform to specialized cells such as blood cells, muscle cells, skin, organ tissues, etc. There are different types of stem cells that can be found in different parts of the body. They can be found in 4-5 day old embryos (totipotent) which have the highest potential for use in regenerating or repair diseased organs and tissues. Adult stem cells are found in several parts of the body including the bone marrow, the placenta and umbilical cords. Amniotic stem cell from the amniotic sac of a fetus contains a large amount of stem cells that are able to differentiate to various types of tissues such as nerve, brain, bone and other cells.

How do stem cells know what to differentiate into?