A chromosome is a long, thread-like structure made up of compacted DNA together with proteins called nucleosomes. It is made of two chromatids that are joined together by a centromere. At the end of each chromatid are structures called telomeres. DNA, as we all know, is an organism’s genetic material that makes us who we all are and is found in every cell in your body. DNA has to replicate itself to before a new cell can be made and during each replication, a small piece of DNA at the end doesn’t get replicated. This means that the more cells made the shorter the DNA gets from one cell to the other. Once the DNA starts losing important parts of the sequence due to this shortening, no more cells can be made. This is where telomers come in!
Telomeres are areas of repetitive DNA that are found at the end of chromosomes. They prevent any of the important DNA from being lost by bearing the load of DNA shortening also known as telomere shortening. Telomeres are specifically present to allow new cells to be made without losing any important DNA during DNA replication.
We know that as we grow our body makes more and more cells to accommodate for our growth, injuries, and general maintenance of our body systems. This means that the older we get, the more cells we need which require DNA replication and this subsequently results in telomere shortening. When the telomeres get worn out, the DNA starts shortening the important parts of the sequence until the cells made can no longer survive, no more cells are made. This is called senescence and is the reason we age!
Telomere shortening happens in every single one of our cells and can be used to predict the age of an individual. It happens at different rates in different cells and the rate of telomere shortening can be altered based on our lifestyle choices (diet or exercise). A new study was done by Alessia Mongelli, and her colleagues found that COVID-19 accelerates telomere shortening and your biological age. This means that increased biological age is part of the persistent post-COVID-19 syndrome or the post-COVID-19 symptoms. The faster telomere shortening occurs the faster senescence occurs. When senescence occurs, immune cells stop being produced leads to the development of blood clots and pulmonary, cardiac, and nervous fibrosis which decreases the functioning of organs.
In another study done by Antoine Froidure and his colleagues found that the shorter the telomeres are at the point of infection, the more likely the individual will have severe COVID-19 symptoms along with persistent post-COVID-19 syndrome or symptoms after COVID. This study explains why the older population has been suffering from the more severe COVID-19 symptoms and has been dying at a higher rate compared to younger individuals.
COVID-19 has had a devastating effect on the population and scientists are finding out more about this virus. With the fourth wave in South Africa fast approaching it is crucial to practice COVID regulations. Maintain social distancing, wear a face mask, wash your hands regularly and clean frequently touched surfaces. Stay safe!
https://www.mdpi.com/1422-0067/22/11/6151/htm#B21-ijms-22-06151