Researchers developing a therapy to regenerate lung tissue damaged by severe COVID have postulated that shortened telomeres are associated with the damage.
Telomeres are structures at the ends of chromosomes that maintain their integrity, and a small portion of them are lost with each cell division, such as when regenerating damaged tissue. As the telomere sections shorten, they eventually become unable to divide and are senescent. The team was already working on a way to regenerate lung tissue in pulmonary fibrosis, and adapted their research to the COVID pandemic. In pulmonary fibrosis, lung tissue becomes scarred and rigid, resulting in reduced lung capacity. In previous research, they had shown that telomere damage to the alveolar type II pneumocytes – which happen to be the same cells targeted by SARS-CoV-2.
Maria A Blasco, a researcher at CNIO said, “When I read that type II alveolar pneumocytes were involved in COVID-19, I immediately thought that telomeres might be involved.” The researchers believe short telomeres hinder tissue regeneration after severe COVID.
Blasco explained, “we know that the virus infects alveolar type II pneumocytes and that these cells are involved in lung regeneration; we also know that if they have telomeric damage they cannot regenerate, which induces fibrosis. This is what is seen in patients with lung lesions after COVID-19: we think they develop pulmonary fibrosis because they have shorter telomeres, which limits the regenerative capacity of their lungs.”
To support this, the team analysed the telomeres of 89 COVID patients. Although it might be expected that older patients had shorter telomeres, the researchers found that all of those with severe COVID had shorter telomeres – regardless of age.
The researchers wrote: “These findings demonstrate that molecular hallmarks of aging, such as the presence of short telomeres, can influence the severity of COVID-19 pathologies.”The involvement of shorter telomeres opens up the possibility of using telomerase to lengthen them again, as a potential treatment.The team will now move to an experimental mouse model, infecting mice with short telomeres and no telomerase with COVID, giving telomerase to some to see if the lung tissue can regenerate after severe COVID.
Source:News-Medical.Net
Journal information: Sanchez-Vazquez R, Guío-Carrión A, Zapatero-Gaviria A, Martínez P, Blasco M. Shorter telomere lengths in patients with severe COVID-19 disease. Aging (Albany NY). 2021. doi:10.18632/aging.202463
