New research has shown that anti-HIV drugs may fight macular degeneration – overturning a preconception about DNA in the process.
Macular degeneration is the leading cause of blindness in developed countries. Even though HIV does not cause dry macular degeneration, the drugs prevented the loss of vision.
“We are extremely excited that the reduced risk was reproduced in all the databases, each with millions of patients,” said Jayakrishna Ambati, MD, a leading macular degeneration researcher at the University of Virginia School of Medicine. “This finding provides real hope in developing the first treatment for this blinding disease.”
A Big Data Archeology review of four health insurance databases showed that Nucleoside Reverse Transcriptase Inhibitors (NRTIs), a commonly used HIV treatment, reduced the incidence of dry macular degeneration by 40%. The records spanned two decades and covered over 100 million patients. The drugs had also previously been shown to possibly prevent diabetes.
The finding also comes with the discovery that DNA can be produced inside the cytoplasm. Alu DNA (found exclusively in primates), which makes up 10% of the human genome, is transposable and can insert itself into other places on the genome. It was long considered “junk” DNA, but are now believed to have important functions, such as allowing for multiple expressions of proteins from a single Alu element. Since it cannot replicate itself, Alu DNA requires a transposon called L1 to accomplish this, which was now reported to allow the production of Alu DNA outside the chromosome. The buildup of Alu DNA in cells contributes to macular degeneration, by killing off cells that support the retina.
The researchers are urging further investigation into NRTIs or safer derivatives known as Kamuvudines, both of which block a key inflammatory pathway, can be useful in preventing vision loss from dry macular degeneration.
“A clinical trial of these inflammasome-inhibiting drugs is now warranted,” said Ambati. “It’s also fascinating how uncovering the intricate biology of genetics and combining it with big data archeology can propel insights into new medicines.”
Source: Medical Xpress
Journal Information: Shinichi Fukuda el al., “Cytoplasmic synthesis of endogenous Alu complementary DNA via reverse transcription and implications in age-related macular degeneration,” PNAS (2021). www.pnas.org/cgi/doi/10.1073/pnas.202275111
