This scientists are hoping to open up new paths in a field they may call microbial endocrinology. These viral insulin like peptides are shown to be are able to work on both rodent and human cells in this study, with a large number of microbial peptides to which exposure occurs there is a novel window for host-microbe interactions. Studying of these processes will help to gain a better understanding of the role of microbes in human diseases.
Prior work focused on developing vaccines against bacteria. Hypothesizing whether viruses or bacteria could create insulin like peptides that may trigger disease the team analyzed large scale databases holding viral genomic sequences it was found that various viruses can produce peptides which are similar in part or whole to 16 human hormones and regulatory proteins. 4 viruses came to attention from a family known to infect fish, to find out if these could be active in mammals the team chemically synthesized the viral insulin like peptides.
The team investigated whether the viral insulin like peptides could act like hormones by experimentation in mice and human cells. Results showed that the viral insulin like peptides could bind to human insulin receptors and to receptors for a closely related hormone called insulin-like growth factor 1, which are proteins on cells that them to take up glucose and grow. The peptides could stimulate the signalling pathways inside of cells that were stimulated by insulin-like growth factor 1 and human insulin. Model mice injected with viral peptides were observed to exhibit decreased levels of blood glucose which is a sign of insulin action. Analysis of human intestine virus databases showed evidence of humans being exposed to these viruses.
The scientists search for other viruses that can produce human like hormones is being broadened. It is thought that there may be more than 300,000 viruses that can infect and be carried to mammals, of which about 2.5% of these have been sequenced, thus more viral hormones including viral insulins are expected to be found in the future.
Analyzing viral peptides such as these could eventually lead to drug manufacturers develop new forms of synthesized human insulins, that can be stored for longer periods of time, or don’t require refrigeration, and insulins that may be absorbed more efficiently or degrade slower. The discovery also gives another example of how study in one field can stimulate into another, underscoring the value and importance of cross fertilization in the scientific discovery process.
