COVID-19 Priority Research Paper Volume 13, Issue 18 pp 21838—21854

SARS-CoV-2 causes senescence in human cells and exacerbates the senescence-associated secretory phenotype through TLR-3

Pseudovirus amplifies the SASP in senescent preadipocytes and genetically or pharmacologically inhibiting TLR-3 attenuates this SASP amplification. (A) SASP factors were assayed in senescent and non-senescent preadipocytes (n=4) treated with pseudovirus for 96 hrs. Data are shown as a function of cell number; mean +/- SEM, 2-way repeated measures ANOVA. (B) Senescent cells were transfected with TLR-3 siRNA or treated with TLR-3 antagonist (10μM) and then exposed to pseudovirus for 96 hrs. Data are expressed as a function of untreated senescent cells; mean +/- SEM, repeated 1-way ANOVA and post hoc pairwise comparisons Fischer’s LSD. (C) TLR-3 agonist increases SASP factor expression in senescent (but not non-senescent) human preadipocytes. Senescent and non-senescent preadipocytes were exposed to Poly I:C for 24, 48, or 96 hrs. and analyzed for SASP factors (rtPCR). Data are expressed as a function of untreated senescent cells; mean +/- SEM, repeated 2-way ANOVA and post hoc pairwise comparison Tukey’s HSD. All other significant p values are listed in Supplementary Table 1.

Figure 3. Pseudovirus amplifies the SASP in senescent preadipocytes and genetically or pharmacologically inhibiting TLR-3 attenuates this SASP amplification. (A) SASP factors were assayed in senescent and non-senescent preadipocytes (n=4) treated with pseudovirus for 96 hrs. Data are shown as a function of cell number; mean +/- SEM, 2-way repeated measures ANOVA. (B) Senescent cells were transfected with TLR-3 siRNA or treated with TLR-3 antagonist (10μM) and then exposed to pseudovirus for 96 hrs. Data are expressed as a function of untreated senescent cells; mean +/- SEM, repeated 1-way ANOVA and post hoc pairwise comparisons Fischer’s LSD. (C) TLR-3 agonist increases SASP factor expression in senescent (but not non-senescent) human preadipocytes. Senescent and non-senescent preadipocytes were exposed to Poly I:C for 24, 48, or 96 hrs. and analyzed for SASP factors (rtPCR). Data are expressed as a function of untreated senescent cells; mean +/- SEM, repeated 2-way ANOVA and post hoc pairwise comparison Tukey’s HSD. All other significant p values are listed in Supplementary Table 1.