RESUMEN
OBJECTIVE@#To evaluate the effects of Huoxin Pill (, HXP) on cardiac fibrosis and heart failure (HF) in isoproterenol (ISO)-induced HF rats.@*METHODS@#Thirty Wistar rats were randomly divided into 5 groups including control, HF, isosorbide mononitrate (ISMN), HXP low (HXP-L), and HXP high (HXP-H) groups (n=6 for each group) according to the complete randomization method. Rats were pretreated with ISMN (5 mg/kg daily), low concentration of HXP (10 mg/kg daily) or high concentration of HXP (30 mg/kg daily) or equal volume of saline by intragastric administration for 1 week, followed by intraperitoneal injection of ISO (10 mg/kg, 14 days), and continually intragastric administrated with above medicines or saline for additional 6 weeks. The effects of HXP treatment on the cardiac function, heart weight index (HWI), pathological changes, and collagen content were further assessed. Moreover, the role of HXP on activation of transforming growth factor- β 1 (TGF-β 1)/Smads pathway was further explored using immunohistochemistry (IHC) and Western-blot assay.@*RESULTS@#HXP treatment significantly alleviated the decrease of ejection fraction (EF) and fractional shortening (FS), while decreased the elevation of left ventricular end-systolic volume (LVESV) in ISO-induced HF rats (P<0.05). Moreover, HXP treatment obviously attenuated the increase of HWI and serum level of creatine kinase MB (CK-MB, P<0.05), as well as pathological changes in ISO-induced HF rats. Further determination indicated that HXP treatment alleviated the elevation of collagen I and collagen III protein expression in cardiac tissues of ISO-induced HF rats. Furthermore, HXP treatment significantly down-regulated the increase of TGF-β 1 and p-Smad2/3 protein expression in cardiac tissues of HF rats (P<0.05), while did not affect the expression of total Smad2/3.@*CONCLUSIONS@#HXP attenuated heart failure and cardiac fibrosis in ISO-induced HF rats by suppression of TGF-β 1/Smad2/3 pathway.
RESUMEN
OBJECTIVE@#To study the anti- fibrotic effect of human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-EXOs) and explore the mechanism.@*METHODS@#Twenty-four C57 BL/6 mice were divided into 4 groups (=6), including the control group treated with intratracheal injection of saline (3 mg/kg); lung fibrosis model group with intratracheal injection of 1.5 mg/mL bleomycin solution (prepared with saline, 3 mg/kg); EXOs1 group with intratracheal injection of 1.5 mg/mL bleomycin solution (3 mg/kg) and hUCMSC-EXOs (100 μg/250 μL, given by tail vein injection on the next day after modeling); and EXOs2 group with intratracheal injection of 1.5 mg/mL bleomycin solution (3 mg/kg) and hUCMSC-EXOs (100 μg/250 μL, given by tail vein injection on the 10th day after modeling). At 21 days after modeling, pulmonary index, lung tissue pathology and collagen deposition in the mice were assessed using HE staining and Masson staining. The expression level of TGF-β1 was detected using ELISA, and vimentin, E-cadherin and phosphorylated Smad2/3 (p-Smad2/3) were detected using immunohistochemical staining. CCK8 assay was used to evaluate the effect of hUCMSCEXOs on the viability of A549 cells, and Western blotting was used to detect the expression levels of p-Smad2/3, vimentin, and E-cadherin in the cells.@*RESULTS@#Compared with those in the model group, the mice treated with hUCMSC-EXOs showed significantly reduced the pulmonary index ( < 0.05), collagen deposition, lung tissue pathologies, lowered expressions of TGF-β1 ( < 0.05), vimentin, and p-Smad2/3 and increased expression of E-cadherin. hUCMSC-EXOs given on the second day produced more pronounced effect than that given on the 11th day ( < 0.05). CCK8 assay results showed that hUCMSC-EXOs had no toxic effects on A549 cells ( > 0.05). Western blotting results showed that hUCMSC-EXOs treatment significantly increased the expression of E-cadherin and decreased the expressions of p-Smad2/3 and vimentin in the cells.@*CONCLUSIONS@#hUCMSC-EXOs can alleviate pulmonary fibrosis in mice by inhibiting epithelialmesenchymal transition activated by the TGF-β1/Smad2/3 signaling pathway, and the inhibitory effect is more obvious when it is administered on the second day after modeling.