Fig 2: Validation of Aβ42 fibril-induced microglia genes by immunolabeling. Increased immunolabeling for PAI-1, MMP9, MMP12, CCL2, and C1R co-localized with microglia surrounding amyloid plaques. Brain sections from 15 M WT rats (A,C,E,G,I) and F344Tg-AD rats (B,D,F,H,J) were labeled with mAb66.1 to detect amyloid plaques (blue) and goat polyclonal antibody to Iba1 for microglia (red), as well as rabbit polyclonal antibodies to PAI-1, MMP9, MMP12, CCL2, and C1R (green). Scale bars = 50 µm.

Fig 3: Increased mRNA expression of SASP markers in CS-exposed p16-3MR mice. mRNA expression of SASP markers (IL-1α, IL6, CCL2, CCL5 and MMP12) were measured in the lung tissues from air- and CS-exposed young and old p16-3MR mice. Scatter plot represent the mean normalized fold change of respective air- vs. CS-exposed mouse lungs using ∆∆Ct method. Data are shown as mean ± SEM (n = 3–5/group). * p < 0.05, ** p < 0.01, *** p < 0.001 vs. air as per unpaired t-test.

Fig 4: Sub-chronic e-cig exposure affects protein abundance of matrix metalloproteinases (MMPs) in mouse lungs. Protein levels of several MMPs (MMP9, MMP2, MMP12, and MMP8) were measured in whole mouse lung homogenates via Western blot. Representative blot images and densitometry analyses for female (a) and male (b) mice are shown. β-actin was used as an endogenous control. Data are shown as mean ± SEM. (n = 4–5/group). * P < 0.05 between groups; $ P < 0.05, compared with air exposed WT group; & P < 0.05, compared with PG exposed WT group. # P < 0.05, compared with PG + Nic exposed WT group

Fig 5: Altered protein abundance of SASP-associated markers in CS-exposed p16-3MR mice. Younger and older p16-3MR mice were exposed to sub-chronic CS for 30 days and the expression of SASP-associated markers-MMP9, MMP12, PAI-1 and FN-1-were determined using immunoblotting analyses. β-actin was used as loading controls. The band intensity was measured by densitometry and data were shown as fold change relative to respective control group. Full gels/blots with bands (unedited/uncropped electrophoretic gels/blots) obtained from air- and CS-exposed younger and older mouse samples from the same experiments were processed in parallel and are shown (see Supplementary Materials as Suppl. Figures files). Data are shown as mean ± SEM (n = 4–5/group). * p < 0.05 vs. air as per unpaired t-test.