FIGURE 8

FIGURE 8

MF6 treatment decelerated cardiac aging indices during normative aging in the turquoise killifish. (A) Representative Western blot and quantification analysis of the Fabp7a protein expression in 8‐week‐old versus 16‐week‐old killifish. n = 4, Student t‐test. (B) Schematics of the schedules for Fabp7 inhibitor (MF6) treatment from 12‐week‐old to 16‐week‐old killifish. MF6 was delivered once the other day by oral gavage. Non‐invasive assays refer to in vivo phenotyping methods that live fish can tolerate and survive, such as echocardiography and swimming capacity measurement. Invasive assays involve phenotyping methods that require sacrificing the fish to isolate tissues or organs for histological, molecular, and cellular analyses. (C) Ejection fraction (EF, %) quantification in turquoise killifish treated with MF6 (Fabp7a inhibitor, Fabp7‐i) or DMSO control, measured at 12, 16, and 20 weeks of age, showing significantly preserved cardiac function in the MF6‐treated group at 16 and 20 weeks of age. n = 5–8, two‐way ANOVA. ns, not significant. *, p < 0.05. (D) Swimming capacity assessed as body length per second (BL/s), demonstrating improved physical endurance in MF6‐treated fish at 16 and 20 weeks of age. n = 4–8, two‐way ANOVA. ns, not significant. *p < 0.05. (E, F) Representative images (D) and quantification (E) of senescence‐associated β‐galactosidase (SA‐β‐gal) activity staining in the MF6‐treated hearts compared to the DMSO controls at 20 weeks. Scale bar, 50 μm. n = 3, Student t‐test. (G–I) Representative western blot images (G) and quantification of the Fabp7a (H) and γ‐H2A.X (I) protein levels in the MF6 treated killifish hearts compared to DMSO control. n = 3, Student t‐test. (J–L) Representative images of γ‐H2A.X (J) and p16 (K) antibody immunofluorescent staining and quantification of γ‐H2A.X‐positive and p16 cell numbers (L) in the MF6‐treated killifish hearts compared to DMSO. Scale bars, 20 μm. n = 5, Student t‐test. (M) Quantitative RT‐PCR analysis of cellular senescence markers p21 and p27 and SASP markers including tnf‐α, il‐6, and il‐8 in the MF6 killifish hearts compared to DMSO control. n = 3 biological repeats, student t test.