Cetirizine regulates scleroderma skin fibrosis in mice via the TGF-β1/Smad3 signaling pathway

Objective:To investigate the effect of cetirizine on the fibrosis of skin tissue in systemic sclerosis(SSc)mice and its mechanism of action.Methods:Thirty-two BALB/C mice were randomly divided into a blank group,a model group,a cetirizine low-dose group,and a cetirizine high-dose group,with eight in each group.The blank group was injected with normal saline on the back,and the other three groups were injected with bleomycin on the back to prepare SSc mouse models.The mice were injected once a day for 28 consecutive days,while the normal group and the model group were given saline.The dose group was administrated intragastrically at 2 mg/kg and 5 mg/kg,respectively,for 28 consecutive days.Detect the thickness of the dermis by taking the skin tissue in the back injection area of each group.Hematoxylin-eosin staining(HE)and Masson staining.Sample hydrolysis method to detect hydroxyproline(HYP)content in skin tissue.Immunohistochemical detection ofα-smooth muscle actin(α-SMA)expression in skin tissues.Enzyme-linked immunosorbent assay(ELISA)to detect serum interleukin(IL-6,IL-10)and transforming growth factor(TGF-αand TGF-β1).Quantitative real-time PCR(qRT-PCR)was used to detect the expression levels of collagen type I(COL1A1),type III collagen(COL3A1),Smad homolog 3(Smad3),and TGF-β1 mRNA.Western blot was used to detect the expression levels of COL1A1,COL3A1 and p-Smad3.Results:Compared with the blank group,the dermis thickness and HYP content of the model group increased,the skin tissue lesions and fibrosis were more severe,theα-SMA positive expression intensity in the skin tissue was higher,and the serum IL-6,IL-10,TGF-α,TGF-β1 content increased,COL1A1,COL3A1,Smad3,TGF-β1 mRNA expression levels increased in skin tissues,COL1A1,COL3A1,p-Smad3 protein expression increased,the differences were statistically significant(P<0.05).Compared with the model group,the dermal thickness and HYP content of the low and high dose cetirizine groups were reduced,the degree of skin tissue lesions and fibrosis was improved,the expression ofα-SMA in skin tissues was weakened,the levels of IL-6,IL-10,TGF-α,TGF-β1 in serum were reduced,the expression levels of COL1A1,COL3A1,Smad3 and TGF-β1 in skin tissues were reduced,and the expression levels of COL1A1,COL3A1,and p-Smad3 proteins were reduced,the decrease in the high-dose group was more significant,and the differences were statistically significant(P<0.05).Conclusion:Cetirizine can improve the degree of fibrosis of skin tissue in SSc mice and reduce the immune inflammation response.The mechanism of action is related to the TGF-β1/Smad3 signaling pathway.

Effects of transforming growth factor-β_1 and signal protein Smad3 on rat cardiomyocyte hypertrophy

Background SMAD proteins have recently been identified as the first family of putative transforming growth factor-β_1(TGF-β_1) signal transducers. This study was to investigate the effects of TGF-β_1 and signal protein Smad3 on rat cardiac hypertrophy.Methods The incorporation of [3H]-leucine was measured to determine the hypertrophy of cardiomyocyte incubated with different doses of TGF-β_1 in cultured neonatal cardiomyocytes. The model of rat cardiac hypertrophy was produced with constriction of the abdominal aorta. At different times after the operation, rats were killed, and their left ventricular mass index (LVMI) determined. The mRNA expression of TGF-β_1 and Smad3 of cultured cells and hypertrophic left ventricles were assessed by RT-PCR. The protein expression of Smad3 was assessed by Western blot.Results In cultured neonatal cardiomyocytes, TGF-β_1 significantly promoted incorporation of [3H]-leucine. With the concentration of 3 pg/L, it increased the expression of Smad3 in mRNA and protein levels after 15 minutes, and continued for up to 8 hours of cultured cardiomyocytes. The LVMI and the expression of TGF-β_1 (mRNA) and Smad3 (mRNA and protein) of hypertrophic left ventricle were increased by day 3 after the operation and continued to the 4th week. The peak expression of these was in the second week after operation.Conclusion TGF-β_1 has positive effects on rat cardiomyocyte hypertrophy. Signal protein Smad3 could be related to the pathologic progression of rat cardiac hypertrophy.