Fig. 7: Age-related differences in WAT’s response to SARS-CoV-2 infection in golden hamsters.

Schematic diagram showing the non-depot-specific (left) and the depot-specific (right) effects of a SARS-CoV-2 infection on WAT in young-adult vs. aged golden hamsters. The viral infection perturbed lipid metabolism in both the (inguinal) SCAT and the (epididymal) VAT but induced CLS formation—indicative of infection-induced adipocyte death—in SCAT only. Importantly, massive adipose death was evident in the SCAT of aged hamsters. The repair phase post infection-induced injury was effective in young adults but not in aged animals. We hypothesize that the accumulation of tissue damage in the SCAT of aged animals results from both the defective clearance of dead adipocytes by surrounding macrophages having age-related compromised efferocytic capacity, and/or the absence of replacement of dead adipocytes by newly formed adipocytes due to age-related impaired adipogenesis. CLSs crown-like structures. Preadipocytes are shown in red, and newly formed adipocytes are shown in green. Both non-depot-specific and depot-specific WAT remodeling upon SARS-CoV-2 infection might participate to COVID-19 severity in aged individuals. Created with BioRender.com.