Mounting Clues Show that Virus Could Trigger Diabetes
Evidence from mouse studies shows that a virus transmitted through the intestines could trigger diabetes in people carrying the virus. The study showed that the virus damages insulin-producing cells.
According to a study published in the journal Cell Reports Medicine, the researchers observed that infection with coxsackievirus B type 4 CVB4, a kind of enterovirus, induced URI down-regulation. This protein controls various cellular functions. This down-regulation triggered a cascade of molecular events. The team also observed that the results show that the virus at the heart of Covid-19 could also trigger diabetes.
The Trigger of Diabetes
The scientists in this study were seeking a better understanding of how enteroviruses could trigger Type-1 diabetes. The researchers used mice that had been grafted with human pancreatic cells with CVB4 and human and mouse insulin-producing cells that also had the virus. At the end of several experiments using these infected cells, the team was able to identify a complex chain of events that may account for the trigger of diabetes.
The researchers observed that CVB4 infection-induced down-regulation of URI, a protein that controls various cellular functions. This down-regulation triggered a cascade of molecular events. The result was the silencing of the gene Pdx1, which governs beta cells in the pancreas. These beta cells produce insulin. Dr. Nabil Djouder, a researcher at the Spanish National Cancer Research Center and the lead author of the study, explains:
“Pdx1 silencing causes the loss of the identity and function of the beta cells, which become more like alpha cells, in charge of increasing blood glucose levels, and hence leading to hyperglycemia and subsequent diabetes, independently of any immune reactions.”
High Levels of Blood Sugar
The researchers also noted that mice with diabetes that overexpressed the URI protein were more tolerant of blood sugar changes. The findings indicated a correlation between the expression of URI, Pdx1, and viral particles in pancreata from people with diabetes. For scientists, this suggests a causal relation between human diabetes and enteroviruses.
There is already growing evidence about people who have developed diabetes after being infected with SARS-CoV-2 and evidence from dozens more people with COVID-19 who have arrived in hospital with too high blood sugar levels and ketones are produced from fatty deposits in the liver. When the body doesn’t make enough insulin to break down sugar, it uses ketones as an alternative fuel source.
The Centers for Disease Control and Prevention (CDC) describes diabetes as an ongoing health condition that affects how a person’s body transforms food into energy. When a person consumes food and drinks, their blood sugar increases; their pancreas then produces the hormone insulin, enabling cells to access this blood sugar.
Triggering Functions
However, people with diabetes may not either make good use of insulin (type 2 diabetes) or produce enough of it (type 1 diabetes). Type 2-diabetes is the most common form of diabetes, accounting for approximately 90–95% of all cases of diabetes in the adult population.
According to The American Diabetes Association, both types of diabetes can be caused by a combination of genetic and environmental factors. For type 1 diabetes, scientists believe that viruses are one aspect of these ecological factors even though scientists are not yet sure exactly how this triggering function occurs.