Mechanism of Dahuang Zhechongwan in Treating Myocardial Fibrosis of Rats via TGF-β1/Smads/miR29 Pathway / 中国实验方剂学杂志

ABSTRACT

ObjectiveTraditional Chinese medicine， namely Dahuang Zhechongwan （DHZCW） was used to treat myocardial fibrosis in model rats， observe its effect on myocardial fibrosis in rats， and explore its action mechanism. MethodThirty-six SPF male Kunming rats were divided into blank group， model group， low-， medium-， high-dose groups of DHZCW （0.056， 0.084， 0.168 g·kg-1）， captopril group （10 mg·kg-1）， with six rats in each group. Except for the blank group， the other groups were intraperitoneally injected isoproterenol solution of 5 mg·kg-1 for 15 consecutive days to replicate the myocardial fibrosis model. At the beginning of modeling， the rats in each group took drugs， and they were sacrificed 28 days after administration. Serum and heart tissue were collected for the corresponding detection. Hematoxylin-eosin （HE） staining and Masson staining were used to observe tissue inflammation， cellular degeneration， necrosis， and fibrosis. The contents of hydroxyproline （HYP）， tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， interleukin-6 （IL-6）， hyaluronic acid （HA）， laminin （LN）， type-Ⅲ procollagen （PC Ⅲ） in serum of rats and rats were determined by enzyme-related immunosorbent assay （ELISA）. The expression levels of key pathway proteins transforming growth factor-β1 （TGF-β1）， α-smooth muscle actin （α-SMA）， Smad2， Smad3， and Smad7 were detected by Western blot. The expression levels of key pathway genes TGF-β1， α-SMA， Smad2， Smad3， Smad7， miR-29a-5p， miR-29b-2-5p， and miR-29c-5p were detected by Real-time quantitative polymerase chain reaction （Real-time PCR）. ResultCompared with the blank group， the pathological changes of fibrosis in the model group were obvious， the contents of serum HYP， TNF-α， IL-1β， IL-6， HA， LN， and PCⅢ were increased （P<0.01）， the protein expression levels of TGF-β1， α-SMA， Smad2， and Smad3 were increased； the protein expression level of Smad7 was decreased （P<0.01）. The mRNA expression levels of TGF-β1， α-SMA， Smad2， and Smad3 were increased （P<0.05， P<0.01）， while those of Smad7， miR-29a-5p， miR-29b-2-5p， and miR-29c-5p were decreased （P<0.01）. Compared with the model group， after 28 days of administration， serum HYP， TNF-α， IL-1β， IL-6， HA， LN， and PCⅢ in high-， medium-， and low-dose groups of DHZCW and captopril groups were decreased （P<0.01）. Except for the low-dose group， the protein contents of TGF-β1， α-SMA， Smad2， and Smad3 were decreased， while the protein content of Smad7 was increased （P<0.01）. The mRNA expression levels of TGF-β1， Smad2， α-SMA， and Smad3 in high-dose group of DHZCW were decreased （P<0.05，P<0.01）， while those of Smad7， miR-29a-5p， miR-29b-2-5p， and miR-29c-5p were increased （P<0.05）. The mRNA expressions of TGF-β1， Smad2， and Smad3 in the medium-dose group of DHZCW were decreased （P<0.05， P<0.01）， while mRNA expression of Smad7 was increased （P<0.01）. The mRNA levels of TGF-β1 and Smad2 in the low-dose group of DHZCW were decreased （P<0.01）. ConclusionDHZCW can improve myocardial fibrosis in rats， and its action mechanism may be related to the regulation of the TGF-β1/Smads/miR-29 pathway. In addition， there is dose dependence in the range of 0.056-0.168 g·kg-1， and the effect of the high-dose group is more stable.