Effects of TRAM-34 on mesangial cell hypertrophy induced by TGF-β1

Objective: To investigate the effects of TRAM-34 on TGF-β1-induced mesangial cell hypertrophy to probe the role of K_Ca3.1 in glomerulosclerosis. Methods: After 2 ng/mL TGF-β1 was used to induce mesangial cell hypertrophy/proliferation, the effects of 8 nmol/L, 16 nmol/L and 24 nmol/L TRAM-34 upon cell cycle and cell proliferation were observed using flow cytometry and MTT. Then the most effective dosage of TRAM-34 was identified and the mRNA of α-SMA and FSP-1 was tested by RT-PCR. Results: The hypertrophy of mesangial cells induced by 2 ng/mL TGF-β1 was blocked at G0-G1 phase control vs. TGF-β1: (48.45±1.89)% vs. (70.29±1.84)%; P<0.01. At S phase, the percentage of cells declined correspondingly control vs. TGF-β1: (38.54±1.13)% vs. (19.56±1.67)%; P<0.01. Different concentrations (8, 16 and 24 nmol/L) of TRAM-34 improved the mesangial cell arrest at G0-G1 phase. Of them, the effect was the most obvious in 24 nmol/L group TGF-β1 vs. TRAM-34; G0-G1 phase, (70.29±1.84)% vs. (61.90±1.88)%; S phase, (19.56±1.67)% vs. (25.52±1.62)%; P<0.05. MTT assay showed the similar results that the inhibition in 24 nmol/L group was obviously higher than in 8 nmol/L and the 16 nmol/L groups (P<0.01). And the inhibitory effects of 24 nmol/L TRAM-34 on α-SMA and FSP-1 mRNA expressihons were also greater (P<0.05). Conclusion: TRAM-34 may improve TGF-β1-induced mesangial cell hypertrophy, cellular phenotype transformation and premature senescence.