Effects of STS on cell proliferation and cell cycle distribution.

(A) STS inhibits HG-induced VSMC proliferation. VSMCs were treated with different concentration of STS for 2 h before exposed to HG for 48 h. Cell proliferation was evaluated with the MTT assay. Relative proliferation activities were expressed using untreated control cells as a standard. Values are presented as mean values ± SD. ^###p<0.001 vs control. ^*p<0.05, ^**p<0.01 vs HG group. (B) VSMC counts in the G₀/G₁, S, and G₂/M phases are shown for normal, high glucose, and different doses of STS. Quantitative assessment of the percentage of VSMCs at G₀/G₁, S, and G₂/M phases is shown (C–E). G₀/G₁ phase is represented by the first peak, S phase in diagonal and and G₂/M phase by the second peak. Cell counts were increased in the G₀/G₁ phase and deceased in S and G₂/M phases, compared with the high glucose group, indicating that STS induces cell cycle arrest at the G₀/G₁ phase in a dose-dependent manner. Values are presented as means ± SD. ^###p<0.01 vs control. ^**p<0.01, ^***p<0.01 vs HG group.