Human endogenous retroviruses and the inflammatory response: A vicious circle associated with health and illness.

Human Endogenous Retroviruses (HERVs) are derived from ancient exogenous retroviral infections that have infected our ancestors' germline cells, underwent endogenization process, and were passed throughout the generations by retrotransposition and hereditary transmission. HERVs comprise 8% of the human genome and are critical for several physiological activities. Yet, HERVs reactivation is involved in pathological process as cancer and autoimmune diseases. In this review, we summarize the multiple aspects of HERVs' role within the human genome, as well as virological and molecular aspects, and their fusogenic property. We also discuss possibilities of how the HERVs are possibly transactivated and participate in modulating the inflammatory response in health conditions. An update on their role in several autoimmune, inflammatory, and aging-related diseases is also presented.

Older Women Who Practiced Physical Exercises before the COVID-19 Pandemic Present Metabolic Alterations and Worsened Functional Physical Capacity after One Year of Social Isolation.

BACKGROUND: Because the consequences of the lifestyle changes in older adults associated with the social isolation imposed in response to the COVID-19 pandemic are not fully understood, here, we investigated the effects of one year of social isolation imposed by COVID-19 on the metabolic parameters and functional physical capacity of older women who regularly practiced physical exercises before the pandemic. METHODS: Systemic lipid and protein profiles, estimated creatinine clearance (ECC), and functional physical capacity (FPC) were assessed before (January-February 2020) and 12 months after social isolation in 30 older women (mean age 73.77 ± 6.22) who were engaged in a combined-exercise training program for at least 3 years before the COVID-19 pandemic. RESULTS: In this group, we observed increased plasma levels of triglycerides and creatinine, an increase in the time necessary to perform gait speed and time-up-and-go tests, and reduced muscle strength assessed by the handgrip test and ECC post-COVID-19 pandemic relative to values recorded pre-pandemic. In addition, we observed significant correlations (both negative and positive) between anthropometric, some metabolic parameters, and physical tests. CONCLUSION: One year of interruption of physical exercise practice imposed in response to the COVID-19 pandemic significantly altered some systemic metabolic parameters and worsened ECC and FPC in older women.