Research of lactate inhibiting the fibrotic phenotype of cardiac fibroblasts
Objective To investigate the regulatory effect and possible mechanism of lactic acid on the fibrotic phenotype of cardiac fibroblasts.Methods Mouse cardiac fibroblasts(mCFs)were divided into control group(conventional culture),experimental-L group(4 mmol·L-1 L-lactic acid),experimental-M group(8 mmol·L-1 L-lactic acid),experimental-H group(12 mmol·L-1 L-lactic acid),transforming growth factor-β1(TGF-β1)group(10 ng·mL-1 TGF-β1),combined group(10 ng·mL-1 TGF-β1+12 mmol·L-1 L-lactic acid)and monocarboxylate transporter inhibitor(CHC)group(3 mmol·L-1 CHC).Western blot was used to detect the expression of fibrosis-related proteins and pan-lactate modification(Pan Kla)and H3 histone K18 lactate modification;cell scratch assay was used to detect cell migration ability.Results The cell migration rates of the control group,TGF-β1 group,experimental-H group and combined group were(40.56±0.03)%,(61.61±0.04)%,(26.59±0.05)%and(38.33±0.06)%,respectively.Compared with the control group,TGF-β1 group and experimental-H group,TGF-β1 group and combined group,the differences were statistically significant(all P<0.01).The relative expression levels of collagen type Ⅰ alpha 1(COL1A1)protein in the control group,TGF-β1 group,experimental-H group and TGF-β1+experimental-H group were 0.76±0.09,1.10±0.07,0.40±0.04 and 0.68±0.10,respectively;the relative expression levels of COL3A1 protein were 0.87±0.05,1.15±0.07,0.32±0.07 and 0.73±0.06,respectively;the relative expression levels of α-smooth muscle actin(α-SMA)protein were 0.86±0.04,1.24±0.09,0.30±0.05 and 0.74±0.08,respectively.Compared with the control group,the above indexes of the TGF-β1 group and the experimental-H group were significantly different from those of the control group,and the above indexes of the TGF-β1 group were significantly different from those of the combined group(all P<0.01).The cell migration rates of mCFs in the control group,experimental-H group and CHC group were(62.60±6.50)%,(28.00±8.15)%and(39.40±4.50)%,respectively;the relative expression levels of COL1A1 protein were 1.10±0.07,0.49±0.04 and 0.34±0.06,respectively;the relative expression levels of COL3A1 protein were 1.04±0.10,0.60±0.20 and 0.37±0.03,respectively;the relative expression levels of α-SMA protein were 1.20±0.11,0.67±0.20 and 0.48±0.18,respectively;the modification levels of Pan Kla were 1.06±0.07,1.54±0.09 and 1.53±0.12,respectively;the modification levels of H3K18la protein were 0.67±0.06,1.23±0.06 and 1.14±0.08,respectively.The above indexes of CHC group and experimental-H group were significantly different from those of control group(all P<0.01).Conclusion L-lactic acid may play a role in inhibiting the fibrosis phenotype of mCFs by increasing non-histone lactic acid modification and H3K18la modification.