Why Elderly, Diabetic Are At Higher Risk Of Covid Infection?
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Researchers have identified that low microRNA (miRNA) immunity increases the risk of Covid-19 infection in older adults and people with diabetes. MicroRNAs are a key class of gene expression regulators which play an important role in inflammation and immune response. The study identified four circulating miRNAs — miR-7-5p, miR-24-3p, miR-145-5p and miR-223-3p — which are high in healthy people and much lower in older people and diabetic patients.

These miRNAs could effectively inhibit SARS-CoV-2 replication by directly targeting the S protein, said Chen-Yu Zhang from the varsity’s School of Life Sciences. Serum exosomes containing these miRNAs from young people could strongly inhibit SARS-CoV-2 replication, but this inhibitory effect was low in older people and diabetic patients, the researchers said.

Long-term exercise was found to increase the level of these miRNAs in the blood offering better protection against the SARS-CoV-2 virus. The team found that three out of the four circulating miRNAs are significantly increased in the serum of healthy volunteers after 8-weeks’ continuous physical exercise. Serum exosomes isolated from these volunteers also showed stronger inhibitory effects on S protein expression and SARS-CoV-2 replication.

The study also provides an interesting observation that continuous physical exercise could boost miRNA immunity against SARS-CoV-2, which gives you another reason to hit the gym after work. Working out every day would therefore help all of us, old or young, to stay out of Covid-19’s way. Further, the findings also demonstrates for the first time that our own endogenous miRNAs could directly inhibit SARS-CoV-2 virus.

The study indicates that miRNAs are an important component of the endogenous RNA-based immune system to fight virus infection. This new understanding of miRNA function may provide new perspectives for prevention, surveillance and treatment of Covid-19, Zhang added.