Four Viruses That Infect Fish Found To Produce Insulin-Like Peptides

Scientists associated with the Joslin diabetes center have discovered that four viruses produced insulin-like peptides, which lowered blood glucose levels in mice and could possibly play a role in the development of certain metabolic diseases and cancers in humans. The scientists evaluated the gene sequences of viruses and found four viruses that normally infect fish with insulin-like sequences in their genes. These viruses produced proteins that resemble insulin, called insulin-like peptides. The peptides were also found to be functionally similar to insulin. When the peptides were tested on cells in the laboratory, they could attach themselves to certain points on the cells called insulin receptors and insulin-like growth factor-1 receptors and stimulate signaling pathways within the cell in a similar way like insulin. When injected into mice, they reduced blood glucose level.

Though the viruses do not directly infect humans, there is possibility that they could pass on to humans on consuming fish infected with the viruses and could affect human cells. The scientists found evidence of the presence of the viruses in the digestive tract of humans. It is possible that the peptides could play a role in the development of disease conditions like metabolic conditions, autoimmune diseases and cancer.

The findings of the study have opened up several new avenues for research. For example:

• The genetic information of more viruses can be evaluated to find out whether they produce similar peptides.
• Analysis of the insulin-like peptides could help to develop new synthetic insulins with better shelf-lives and better pharmacokinetic properties.
• Peptides having similar action can be evaluated to find out whether they could stimulate an autoimmune reaction in type 1 diabetes, or protect against diabetes. They could also be evaluated for their possible protective or contributing role in the development of other metabolic conditions like type 2 diabetes and obesity.
• The insulin-like hormones can be evaluated to find out whether they could stimulate the growth of polyps or cancers in the digestive tract or can be absorbed from the digestive tract and affect other cells of the body.

About Insulin and Type 1 diabetes

Insulin is a hormone that is secreted by the special cells of the pancreas, an organ located in the abdomen. It binds to special sites on each cell of the body called insulin receptors. The binding acts as a ticket for the gate of the cell to open so that glucose from the blood can pass into the cell, and be subjected to various chemical processes so that it can be utilized to produce energy, or stored for future use. Reduced blood levels of insulin result in a condition called type 1 diabetes, characterized by high blood glucose levels.

Reference:

1. Insulin Goes Viral - (http://www.joslin.org/news/virus-can-produce-insulin-like-hormones-active-on-human-cells.html)

Source-Medindia