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.

Prevention and treatment for radiation-induced skin injury during radiotherapy

The skin tissue has the largest area in the human body and functions as both a barrier and a defender.As such,it tends to be the first tissue to be damaged.Advances in medical technology provide prospects as well as side effects,for example,radiation therapy for cancer.With increasing cancer morbidity and radiation widely applied for cancer therapy,radiation-induced skin injury(RSI)has become a serious concern.In recent decades,research efforts have focused on the mechanisms underlying RSI.This review summarizes the mainstream opinions on these mechanisms,including the pathological,molecular biological,and cytobiological alterations.Radiationinduced reactive oxygen species(ROS),cytokines and involved signaling pathways are evaluated.Other relevant aspects include radiation-induced skin fibrosis(RSF)and radiation-related skin cell senescence.Moreover,we review strategies for the prevention and treatment in clinical and pre-clinical studies to support the treatment of RSI during radiotherapy.The prevention strategies include dose control,pre-irradiation instructions,and RSI assessments,while the main treatments include physical therapy,external-use dressings or creams,biological therapy and surgical reconstruction.