Fig. 6

During aging, all three monocyte subsets exhibited several hallmarks of senescence and nonclassical subset was the most prominent. A. β-galactosidase activities of three monocyte subsets in young (21–30 years, n = 12) and older (60–70 years, n = 12) individuals. B. ROS contents of three monocyte subsets between young (21–30 years, n = 12) and elderly (60–70 years, n = 12) individuals. C. Mitochondrial contents of three monocyte subsets in young (21–30 years, n = 12) and old (60–70 years, n = 12) individuals. D. MMPs of three monocyte subsets between young (21–30 years, n = 12) and elderly (60–70 years, n = 12) individuals. E. The ratios of MMP to mitochondrial content in three monocyte subsets between young (21–30 years, n = 12) and aged (60–70 years, n = 12) individuals. F. The intracellular IL-6 levels of three monocyte subsets between young (21–30 years, n = 12) and older (60–70 years, n = 12) individuals. G. The plasma IL-6 levels between young (21–30 years, n = 51) and elderly (58–83 years, n = 50) individuals. H. Correlation of plasma IL-6 levels and age in the older group (58–83 years, n = 50). Blue dots symbolize young adults and orange dots denote aged individuals, ^*P < 0.05, ^**P < 0.01, ^***P < 0.001, ^****P < 0.0001