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If you ask a diabetic patient what hurdles they need to go through continuously as a patient, you are most likely to get an answer that indicates the unavailability and high price of insulin. You must have heard the name ‘insulin’, which is a hormone produced by a lot of mammals including humans. In easier words, insulin is a peptide hormone produced by pancreatic beta cells that helps to use or store glucose.
Type 1 diabetics are unable to rely on their own supply of insulin and require commercially produced, injectable insulin to survive, and so do some people with type 2 diabetes. Only over half of the 150–200 million people who need insulin globally, according to WHO, are receiving treatment with it. Many low and middle-income countries, as well as some high-income countries, still lack adequate access to insulin. The reasons for its high cost and lack of availability are well known. You would know better if you had a patient in your home!
But what if you were told that you can get insulin from cow milk? Yes, it might sound like a dream but it’s not anymore, not for long. Milk is generally not present in the diet of a diabetic patient due to its rich composition of glucose. But maybe milk can be the solution to treating diabetes in future. How?
An ordinary brown bovine from the south of Brazil has made history, being the first transgenic cow to produce human insulin in her milk. Researchers from Universidade de São Paulo and the University of Illinois Urbana-Champaign have pioneered this innovation, which might potentially usher in a new age in insulin production and eventually eliminate medicine scarcity and high costs for diabetics.
Lead author of the study, Matt Wheeler highlighted the creation of the insulin-producing cow, a proof-of-concept accomplishment that might be expanded upon with FDA approval and more research. He said: “Using a DNA construct specific to mammary tissue means there’s no human insulin circulating in the cow’s blood or other tissues. It also takes advantage of the mammary glands capabilities for producing large quantities of protein.”
At first, the researchers made an unsuccessful effort to impregnate the cow using conventional artificial insemination methods once she reached adulthood. Instead, they used hormones to stimulate her initial lactation. There was some milk produced throughout the lactation, but not as much as would happen following a good pregnancy. Nevertheless, the milk contained remarkably high levels of human pro-insulin and insulin. “Our goal was to make pro-insulin, purify it out to insulin, and go from there,” said Wheeler. “But the cow basically processed it herself. She makes about three-to-one biologically active insulin to pro-insulin. The mammary gland is a magical thing.”
During the experiment, cell nuclei of ten cow embryos were treated with a segment of human DNA which codes for pro-insulin, a protein that is the precursor to the active form of insulin, by Wheeler's colleagues in Brazil. There, those were put into the uteruses of regular cows, and one transgenic calf was delivered as a result. Modern genetic engineering techniques allowed human DNA specifically to be targeted for expression in mammary tissue only.
The team hopes to re-clone the cow and to have more success with full lactation cycles and conception in the resulting offspring. According to Wheeler, even a small herd may easily outcompete the current insulin production methods without the need for highly sophisticated equipment or facilities.