Expression analysis of a-smooth muscle actin and tenascin-C in the periodontal ligament under orthodontic loading or in vitro culture

α-smooth muscle actin （α-SMA） and tenascin-C are stress-induced phenotypic features of myofibroblasts. The expression levels of these two proteins closely correlate with the extracellular mechanical microenvironment. We investigated how the expression of α-SMA and tenascin-C was altered in the periodontal ligament （PDL） under orthodontic loading to indirectly reveal the intrinsic mechanical microenvironment in the PDL. In this study, we demonstrated the synergistic effects of transforming growth factor-β1 （TGF-β1） and mechanical tensile or compressive stress on myofibroblast differentiation from human periodontal ligament cells （hPDLCs）. The hPDLCs under higher tensile or compressive stress significantly increased their levels of α-SMA and tenascin-C compared with those under lower tensile or compressive stress. A similar trend was observed in the tension and compression areas of the PDL under continuous light or heavy orthodontic load in rats. During the time-course analysis of expression, we observed that an increase in α-SMA levels was matched by an increase in tenascin-C levels in the PDL under orthodontic load in vivo. The time-dependent variation of α-SMA and tenascin-C expression in the PDL may indicate the time-dependent variation of intrinsic stress under constant extrinsic loading.

Epigallocatechin-3-gallate suppresses transforming growth factor-beta signaling by interacting with the transforming growth factor-beta typeⅡreceptor

AIM: To investigate the(-)-epigallocatechin-3-gallate(EGCG) binding to transforming growth factor-β(TGF-β) type Ⅱ receptor(TGFRⅡ).METHODS: The expression of α-smooth muscle actin(α-SMA) was used as a marker for fibrotic change inhuman lung fibroblast MRC-5 cells. The α-SMA expression level was determined by western blotting and immunohistological analysis. We examined whether the anti-fibrotic effects of EGCG on MRC-5 cells was dependent on antioxidant mechanism by using edaravone and N-acetylcysteine(NAC). The suppression effects of EGCG on Smad2/3 activation were studied by confocal fluorescence microscopy. The binding of EGCG to recombinant TGFRⅡ protein was analyzed by immunoprecipitation and affinity chromatography.RESULTS: When MRC-5 cells were treated with TGF-β, EGCG decreased the expression of α-SMA in a dose dependent manner, whereas catechin did not influence the α-SMA expression in the cells. Except for EGCG, antioxidant compounds(e.g., edaravone and NAC) had no effects on the TGF-β-induced α-SMA expression. Nuclear localization of phosphorylated Smad2/3 was observed after TGF-β treatment; however, EGCG treatment attenuated the nuclear transportation of Smad2/3 in the presence or absence of TGF-β. After a TGFRⅡ expression vector was introduced into COS-7 cells, cell lysates were untreated or treated with EGCG or catechin. The immunoprecipitation experiments using the lysates showed that EGCG dose-dependently bound to TGFRⅡ and that catechin did not at all. Affinity chromatography study indicated that EGCG would bind to TGFRⅡ.CONCLUSION: Our results demonstrate that EGCG interacts with TGFRⅡ and inhibits the expression of α-SMA via the TGF-β-Smad2/3 pathway in human lung fibroblast MRC-5 cells.

Emodin protects rat liver from CCl_4-induced fibrogenesis via inhibition of hepatic stellate cells activation

AIM： To investigate the role of emodin in protecting the liver against fibrogenesis caused by carbon tetrachloride （CCh） in rats and to further explore the underlying mechanisms. METHODS： Rat models of experimental hepatic fibrosis were established by injection with CCh; the treated rats received emodin via oral administration at a dosage of 20 mg/kg twice a week at the same time. Rats injected with olive oil served as a normal group. Histopathological changes were observed by hematoxylin and eosin staining. The activities of alanine aminotransferase （ALT） and aspartate aminotransferase （AST） in serum and hepatic hydroxyproline content were assayed by biochemical analyses. The mRNA and protein relevant to hepatic stellate cell （HSC） activation in the liver were assessed using real-time reverse transcription-polymerase chain reaction （RT-PCR）, immunohistochernistry, western blotting and enzymelinked immunosorbent assay.RESULTS： The degree of hepatic fibrosis increased markedly in the CCh group compared to the normal group （P 〈 0.01）, and decreased markedly in the emodin group compared to the CCI4 group according to METAVIR scale （P 〈 0.01） compared with those in the normal control group （51.02 ± 10.64 IU/L and 132.28 ± 18.14 IU/L）. The activities of serum ALT and AST were significantly higher in rats injected with CCh （289.25 ± 68.84 IU/L and 423.89 ± 35.67 IU/L, both P 〈 0.05）. The activities of serum ALT and AST were significantly reduced by administration of emodin （176.34 ± 47.29 IU/L and 226.1 ± 44.52 IU/L, both P 〈 0.05）. Compared with the normal controls （54.53 ± 13.46 mg/g）, hepatic hydroxyproline content was significantly higher in rats injected with CCI4 （120.27 ± 28.47 mg/g, P 〈 0.05）. Hepatic hydroxyproline content was significantly reduced in the rats treated with emodin at 20 mg/kg （71.25 ± 17.02 mg/g, P 〈 0.05）. Emodin significantly protected the liver from injury by reducing serum AST and ALT activities and reducing hepatic hydroxyproline content. The mRNA levels of transforming growth factor-β1 （TGF-β1）, Smad4 and α-SMA in liver tissues were significantly down-regulated in SD rats that received emodin treatment. Furthermore, significant down-regulation of serum TGF-β1 protein levels and protein expression of Smad4 and α-SMA in liver tissues was also observed in the rats. Emodin inhibited HSC activation by reducing the abundance of TGF-β1 and Smad4. CONCLUSION： Emodin protects the rat liver from CCI4-induced fibrogenesis by inhibiting HSC activation. Emodin might be a therapeutic antifibrotic agent for the treatment of hepatic fibrosis.

Effects of interleukin-10 on activation and apoptosis of hepatic stellate cells in fibrotic rat liver

AIM： TO study the effects of interleukin-10 （IL-10） on the expression of o-smooth muscle actin （α-SMA）, nuclear factor-κB（NF-κB） and Fas/Fas ligand （FasL） in hepatic stellate cells of experimental rats with hepatic fibrosis. METHODS： Sixty clean SD rats were randomly divided into control group （group N）, liver fibrotic group （group C） and IL-10 treatment group （group I）. Control group received intraperitoneal injection of saline （2ml·kg^-1）, twice a week. Fibrotic group was injected intraperitoneally with 50% carbon tetrachloride （CCh） （2 ml·kg^-1）, twice a week. IL-10 treatment group was given IL-10 at a dose of 4 pg·kg^-1 20 minutes before CCl4 administration from the third week. Hepatic stellate cells （HSCs） were isolated from these rats at the seventh and eleventh weeks during the course of liver fibrosis, respectively. The expression of α-SMA and NF-κB in HSCs was measured by S-P immunohistochemistry. The expression of Fas and FasL mRNA was measured by RT-PCR. Furthermore, liver tissues were harvested from three groups at the same time. RESULTS： The CCh- induced experimental rat hepatic fibrosis model was established successfully. The purity of extracted hepatic stellate cells was about 95% and the yield of hepatic stellate cells was 1.2-2.3×10^6/g liver tissue averagely. The positive expression of α-SMA and NF-κB was 36.5% and 28.5% respectively in group N. The positive levels of α-SMA and NF-κB were increased significantly in group C compared to group N （P〈0.01）. The positive signals decreased significantly （P〈0.05） in group I. In the 11^th week, the HSCs of group I became round with visible pyknotic nuclei. The expression of NF-κB in group C was significantly increased in a timedependentmanner （P〈0.01）, but there was no difference in the α-SMA expression （P〉0.05）. The mRNA of Fas and FasL in group C was significantly increased in a timedependent manner compared to that in control group. After treated with IL-10, the expression level of Fas and FasL was higher in group I than in group C. CONCLUSION： The positive expression of α-SMA and NF-κB in hepatic stellate cells is decreased by ectogenic IL-10 in liver fibrosis induced by CCh. The expression of Fas and FasL is increased in the course of liver fibrosis, and is further increased by IL-10. IL-10 could inhibit the activation of HSCs and cause apoptosis of activated HSCs.

Dynamic Variation of RAS on Silicotic Fibrosis Pathogenesis in Rats

The dynamic variation of renin-angiotensin system (RAS) in silicosis remains unclear.Seventy Wistar rats were divided into 7 groups including control group,silicosis groups (inhaling SiO2 for 2,4,8,16 and 24 weeks,respectively) and Captopril (Cap) group.Rat lung primary fibroblasts were divided into control group,SiO2-stimulated group (0,0.5,1,3,6,12,24 and 48 h) and Cap group.The silicotic nodules were formed and collagens were deposited gradually in silicosis group observed by haematoxylin and eosin (HE) staining and Van Gieson (VG) staining.Cap relieved the lung fibrosis and collagen deposition.Immunohistochemistry indicated the positive expression of α-smooth muscle actin α-SMA) was increased gradually in silicotic rat lung tissue.Western blotting revealed the expression of collagen type Ⅰ(Col Ⅰ) and α-SMA was up-regulated in silicotic rat lung tissue and fibroblasts stimulated by SiCh.Cap decreased the expression of Col Ⅰ and α-SMA in silicotic rat lung tissue and fibroblasts stimulated by SiCh.Western blotting also demonstrated the expression of angiotensin-converting enzyme (ACE) and angiotensin Ⅱ type 1 receptor (ATI) was increased,and the expression of ACE2 and Mas was decreased gradually in silicotic rat lung tissue and fibroblasts stimulated by SiCh.ELISA showed the serum levels of ACE and angiotensin Ⅱ(Ang Ⅱ) were also increased and ACE2 and Ang (1 -7) were decreased in the silicosis group.Treatment with Cap decreased the expression levels of ACE,Ang Ⅱ and ATI,and increased the expression levels of ACE2,Ang (1-7) and Mas.These findings suggested that an imbalance between ACE-Ang Ⅱ-AT1 axis and ACE2-Ang (l-7)-Mas axis may participate in the development of silicosis.

Effects of pharmacological serum from normal and liver fibrotic rats on HSCs

AIM: To make drug sera of Salvia miltiorrhiza and Yigankang, both of which are Chinese herbs that activate bleeding and eliminate stasis, in normal rats and those with liver fibrosis, respectively. To investigate and compare the effects of the two different drug sera on the proliferation and activation of hepatic stellate cells (HSCs). METHODS: Some rats were induced with liver fibrosis: 40% carbon tetrachloride (CCI4) subcutaneous injection, twice a week for 9 wk. Salvia miltiorrhiza, Yigankang, colchicines and normal saline were administered into the stomachs of normal rats and those with liver fibrosis. Drug sera were extracted 5 d later. HSCs in vitro were cultivated in different drug sera for 24 h. The rates of proliferation and expression of a-smooth muscle actin (α-SMA) were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and immunocyt-ochemistry stain, respectively. RESULTS: The drug sera from normal and liver fibrotic rats could be used to cultivate HSCs and to observe the effects of the corresponding components of herbs on HSCs. Salvia miltiorrhiza and Yigankang had better inhibitory effects on HSCs than colchicines (MTT: normal drug serum: Salvia miltiorrhiza 0.42 ±0.08, Yigankang 0.32±0.10 vs colchicines 0.45±0.12 pathological drug serum: Salvia miltiorrhiza 0.33±0.02, Yigankang 0.26±0.01 vs colchicines 0.41±0.09. P<0.05). The drug sera of Salvia miltiorrhiza, Yigankang from liver fibrotic rats had a stronger inhibitory effect than the same ones from normal rats (MTT: Salvia miltiorrhiza: normal drug serum 0.42±0.08 vs pathological drug serum 0.33±0.02. Yigankang: normal drug serum 0.32±0.10 vs pathological drug serum 0.26±0.01. P<0.05) CONCLUSION: Salvia miltiorrhiza and Yigankang could inhibit the expression of a-SMA and the proliferation of HSCs. The drug sera from normal and liver fibrotic rats had different effects on HSCs, probably due to different metabolic processes, effective components and different quantities of drug contents in drug sera from rats with different states of liver.

Gardenia jasminoides attenuates hepatocellular injury and fibrosis in bile duct-ligated rats and human hepatic stellate cells

AIM:To investigate the anti-hepatofibrotic effects of Gardenia jasminoides in liver fibrosis.METHODS:Male Sprague-Dawley rats underwent common bile duct ligation(BDL) for 14 d and were treated with Gardenia jasminoides by gavage.The ef-fects of Gardenia jasminoides on liver fibrosis and the detailed molecular mechanisms were also assessed in human hepatic stellate cells(LX-2) in vitro.RESULTS:Treatment with Gardenia jasminoides decreased serum alanine aminotransferase(BDL vs BDL + 100 mg/kg Gardenia jasminoides,146.6 ± 15 U/L vs 77 ± 6.5 U/L,P = 0.0007) and aspartate aminotransferase(BDL vs BDL + 100 mg/kg Gardenia jasminoides,188 ± 35.2 U/L vs 128 ± 19 U/L,P = 0.005) as well as hydroxyproline(BDL vs BDL + 100 mg/kg Gardenia jasminoides,438 ± 40.2 μg/g vs 228 ± 10.3 μg/g liver tissue,P = 0.004) after BDL.Furthermore,Gardenia jasminoides significantly reduced liver mRNA and/or protein expression of transforming growth factor β1(TGF-β1),collagen type?Ⅰ?(Col?Ⅰ) and α-smooth muscle actin(α-SMA).Gardenia jasminoides significantly suppressed the upregulation of TGF-β1,Col?Ⅰand α-SMA in LX-2 exposed to recombinant TGF-β1.Moreover,Gardenia jasminoides inhibited TGF-β1-induced Smad2 phosphorylation in LX-2 cells.CONCLUSION:Gardenia jasminoides exerts antifibrotic effects in the liver fibrosis and may represent a novel antifibrotic agent.

The ROCK pathway inhibitor Y-27632 mitigates hypoxia and oxidative stress-induced injury to retinal Müller cells

Rho kinase （ROCK） was the first downstream Rho effector found to mediate RhoA-induced actin cytoskeletal changes through effects on myosin light chain phosphorylation. There is abundant evidence that the ROCK pathway participates in the pathogenesis of retinal endothelial injury and proliferative epiretinal membrane traction. In this study, we investigated the effect of the ROCK pathway inhibitor Y-27632 on retinal Müller cells subjected to hypoxia or oxidative stress. Müller cells were subjected to hypoxia or oxidative stress by exposure to CoCl2 or H2O2. After a 24-hour treatment with Y-27632, the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide assay was used to assess the survival of Müller cells. Hoechst 33258 was used to detect apoptosis, while 2′,7′-dichlorodihydrofluorescein diacetate was used to measure reactive oxygen species generation. A transwell chamber system was used to examine the migration ability of Müller cells. Western blot assay was used to detect the expression levels of α-smooth muscle actin, glutamine synthetase and vimentin. After treatment with Y-27632, Müller cells subjected to hypoxia or oxidative stress exhibited a morphology similar to control cells. Y-27632 reduced apoptosis, α-smooth muscle actin expression and reactive oxygen species generation under oxidative stress, and it reduced cell migration under hypoxia. Y-27632 also upregulated glutamine synthetase expression under hypoxia but did not impact vimentin expression. These findings suggest that Y-27632 protects Müller cells against cellular injury caused by oxidative stress and hypoxia by inhibiting the ROCK pathway.

Daikenchuto (Da-Jian-Zhong-Tang) ameliorates intestinal fibrosis by activating myofibroblast transient receptor potential ankyrin 1 channel

AIM To investigate the anti-fibrotic effects of the traditional oriental herbal medicine Daikenchuto(DKT) associated with transient receptor potential ankyrin 1(TRPA1) channels in intestinal myofibroblasts. METHODS Inflammatory and fibrotic changes were detected in a2,4,6-trinitrobenzenesulfonic acid(TNBS) chronic colitis model of wild-type and TRPA1-knockout(TRPA1-KO) mice via pathological staining and immunoblotting analysis.Ca^(2+) imaging experiments examined the effects of DKT and its components/ingredients on intestinal myofibroblast(In Myo Fib) cell TRPA1 channel function.Profibrotic factors and transforming growth factor (TGF) -β1-associated signaling were tested in an In Myo Fib cell line by q PCR and immunoblotting experiments.Samples from non-stenotic and stenotic regions of the intestines of patients with Crohn’s disease (CD) were used for pathological analysis. RESULTS Chronic treatment with TNBS caused more severe inflammation and fibrotic changes in TRPA1-KO than in wild-type mice.A one-week enema administration of DKT reduced fibrotic lesions in wild-type but not in TRPA1-KO mice.The active ingredients of DKT,i.e.,hydroxyα-sanshool and 6-shogaol,induced Ca^(2+) influxes in In Myo Fib,and this was antagonized by co-treatment with a selective TRPA1 channel blocker,HC-030031.DKT counteracted TGF-β1-induced expression of TypeⅠcollagen andα-smooth muscle actin (α-SMA) ,which were accompanied by a reduction in the phosphorylation of Smad-2 and p38-mitogen-activated protein kinase (p38-MAPK) and the expression of myocardin.Importantly,24-h incubation with a DKT active component Japanese Pepper increased the m RNA and protein expression levels of TRPA1 in In Myo Fibs,which in turn negatively regulated collagen synthesis.In the stenotic regions of the intestines of CD patients,TRPA1 expression was significantly enhanced.CONCLUSION The effects of DKT on the expression and activation of the TRPA1 channel could be advantageous for suppressing intestinal fibrosis,and benefit inflammatory bowel disease treatment.

Myofibroblastic cell activation and neovascularization predict native liver survival and development of esophageal varices in biliary atresia

AIM: To study the relation between collagen 1, &#x003b1;-smooth muscle actin (&#x003b1;-SMA) and CD34 expression and the most essential portoenterostomy (PE) outcomes.

Effects of transforming growth factor β2 and connective tissue growth factor on induction of epithelial mesenchymal transition and extracellular matrix synthesis in human lens epithelial cells

AIM:To Investigate the effects of transforming growth factorβ2(TGF-β2)and connective tissue growth factor(CTGF)on transdifferentiation of human lens epithelial cells(HLECs)cultured in vitro and synthesis of extracellular matrix(ECM).METHODS:HLECs were treated with TGF-β2(0,0.5,1.0,5,10μg/L)and CTGF(0,15,30,60,100μg/L)for different times(0,24,48,72h)in vitro and the expression ofα-smooth muscle actin(α-SMA),the main component of the extracellular matrix typeⅠcollagen(Col-1)and fibronectin(Fn)were measured by using real-time polymerase chain reaction(PCR)and western-blot.RESULTS:TGF-β2 and CTGF significantly increased expression ofα-SMA mRNA and protein(P【0.05,P【0.001),Fn mRNA and protein(P【0.001),Col-1 mRNA and protein(P【0.001).TGF-β2 could induce HLECs expression of CTGF mRNA and protein in dosedependent manner(P【0.05,P【0.001).TGF-β2 and CTGF could induce HLECs to expressα-SMA,Fn and Col-1 in time-dependent manner.Each time of TGF-β2and CTGF induced HELCs expression ofα-SMA,Fn,Col-1 mRNA and protein was significant increase compared with control(P【0.05,P【0.001).CONCLUSION:TGF-β2 and CTGF could induce HLECs epithelial mesenchymal transition and ECM synthesis.

Antifibrotic effect of aloe vera in viral infection-induced hepatic periportal fibrosis

AIM:To investigate the anti-oxidative and anti-fibrotic effects of aloe vera in patients with liver fibrosis.METHODS:Aloe vera high molecular weight fractions(AHM) were processed by patented hyper-dry system in combination of freeze-dry technique with microwave and far infrared-ray radiation.Fifteen healthy volunteers as the control group and 40 patients were included.The patients were randomly subdivided into two equal groups:the conventional group was treated with placebo(starch),and AHM group was treated with 0.15 gm/d AHM,both for 12 consecutive weeks.The patients were investigated before and after treatment.Serum activity of aspartate aminotransferase(AST),alanine aminotransferase(ALT),alkaline phosphatase(ALP),hyaluronic acid(HA),transforming growth factor-β(TGF-β) and matrixmetalloproteinase-2(MMP-2) were determined.The reduced glutathione(GSH) and malondialdehyde(MDA) levels in liver were assayed and the expression of hepatic α-smooth muscle actin(α-SMA) was identified by immunohistochemistry.RESULTS:At the start of the study,the hematoxylin and eosin staining revealed fibro-proliferated bile ductules,thick fibrous septa and dense inflammatory cellular infiltration in the patients before treatment.The use of AHM for 12 wk significantly ameliorated the fibrosis,inhibited the inflammation,and resulted in minimal infiltration and minimal fibrosis compared to the conventional group.The enzyme activities of the liver(ALT,AST and ALP) were attenuated after treatment in both groups,and the decrease in the AHM group was more significant as compared with the conventional group.Similar to the AST,the MDA levels were significantly higher before treatment,and were attenuated after treatment in both groups.In contrast,the hepatic glutathione content in the patients were decreased significantly in the AHM group compared to the controls.The serum levels of the fibrosis markers(HA,TGF-β and MMP-2) were also reduced significantly after treatment.The expression of α-SMA was modified in patients before and after treatment as compared with the normal controls.In the conventional group,there was only thin and incomplete parenchymal α-SMA positive septum joining the thickened centrilobular veins,while in the AHM group,few α-SMA positive cells were present in sinusoid and lobule after treatment.CONCLUSION:Oral supplementation with AHM could be helpful in alleviating the fibrosis and inflammation of hepatic fibrosis patients.

Smoothelin,a new marker to determine the origin of liver fibrogenic cells

AIM: To explore this hypothesis that smooth muscle cells may be capable of acquiring a myofibroblastic phenotype, we have studied the expression of smoothelin in fibrotic conditions.

Effect of NF-κB p65 antisense oligodeoxynucleotide on transdifferentiation of normal human lens epithelial cells induced by transforming growth factor-β2

AIM：To study the inhibition of nuclear factor kappa-B p65（NF-κB p65）antisense oligodeoxynucleotide（ASODN）on transdifferentiation of normal human lens epithelial cells induced by transforming growth factor-β2（TGF-β2）.·M ETHODS：NF-κBp65ASODNand NF-κBp65missense oligodeoxynucleotide（MSODN）were designed and synthesized.Human lens epithelial cell line（HLE B-3）cells were prepared for study and divided into 7 groups.Control group was HLE B-3 cells cultured in dulbecco’s modified eagle medium（DMEM）.T1,T2,and T3 group were HLE B-3 cells cultured in DMEM with 10 ng/m L TGF-β2 for 6h,12h,24h respectively.A＋T group was HLE B-3 cells cultured with 10 ng/m L TGF-β2for 24h after transfected by NF-κB p65 ASODN for 24h.M＋T group was HLE B-3 cells cultured with 10 ng/m L TGF-β2 for 24h after transfected by NF-κB p65 MSODN for 24h.The negative control group was HLE B-3 cells cultured with 10 ng/m L TGF-β2 for 24h after cultured with transfer agent（Hi Per Fect）for 24h.Cell morphology was observed at different time points using an inverted microscope.The expression of NF-κB p65 m RNA was detected with reverse transcription-polymerase chain reaction（RT-PCR）,and the expression ofα-smooth muscle actin（α-SMA）protein was assayed with ELISA.·RESULTS：With the TGF-β2 stimulation prolongation,the expression of NF-κB p65 m RNA and a-SMA protein increased in T1,T2,T3 groups compared with the control group,and the difference was statistically significant（〈0.05）.NF-κB p65 ASODN lowered the expression of NF-κB p65 m RNA andα-SMA protein induced by TGF-β2.NF-κB p65 MSODN and Hi Per Fect did not lower the expression of NF-κB p65 m RNA andα-SMA protein induced by TGF-β2.The difference between control group and A＋T group was not statistically significant（〉0.05）,but the difference among A＋T group and other groups was statistically significant（〈0.05）.·CONCLUSION：NF-κB p65 ASODN could lower the expression of NF-κB p65 m RNA andα-SMA protein induced by TGF-β2,and antagonized TGF-β2-induced transdifferentiation of HLE B-3.NF-κB p65ASODN could be used as a new biological therapeutic target of posterior capsular opacification.

Preventive approach against drug-induced pulmonary fibrosis through the suppression of epithelial-mesenchymal transition

A number of drugs induce pulmonary injury and subsequently lead to serious lung diseases such as pulmonary fibrosis as the adverse drug reactions.However,an effective preventive approach against drug-induced pulmonary fibrosis has not been established due to poor understanding of common preventive targets in a variety of drugs showing pulmonary toxicity.Epithelial-mesenchymal transition(EMT),a cellular phenotypic change of the epithelial to mesenchymal state,contributes to the development of pulmonary fibrosis through the conversion of damaged alveolar epithelium into myofibroblasts.As several drugs with pulmonary toxicity have been reported to induce EMT,EMT serves as a bridge between the drugs and pulmonary fibrosis.Accumulated evidence supports the potential of EMT as a preventive target against drug-induced pulmonary fibrosis.Additionally,since there are mechanistic differences between the main pharmacological effect and EMT induced by the drug,prevention based on EMT suppression would be possible and would contribute to continuous clinical treatment with the drug to avoid EMT-mediated serious pulmonary fibrosis.Furthermore,targeting EMT seems to be adequate for exerting a preventive effect since EMT in damaged alveolar epithelial cells occurs prior to the development of the pathophysiological state of the whole lung in a bleomycin-induced lung injury rat model.This viewpoint deals with the benefits and perspectives of preventive approaches against druginduced pulmonary fibrosis through the suppression of EMT,which has rarely been addressed.

Depressant effect and mechanism of atorvastatin on the chronic rejection of aortic allograft in rats

Objective To investigate the depressant effect and mechanism of atorvastatin on the chronic rejection of aortic allograft in rats. Methods： The models of abdominal aorta transplantation were made with micro-surgery in rats. The recipients were divided into three groups： allograft control group, atorvastatin-treated group and isograft control group. Vascular intimal thickness in all of the groups were observed by histological examination. The expression of PCNA and α-SMA were determined by immunohistochemistry. The content of nitric oxide was determined by nitrate reductase chromatometry. Results： The vascular intimal thickness in rats of atorvastatin-treated group （11.60% ± 2.40% ） were lower than those in allograft control group （34.60 % ± 6.40 % ; P 〈 0.05） and higher than those in isograft control group （1.15 % ± 0.65 %; P〈 0.05 ）. The expression level of PCNA was decreased in atorvastatin-treated group （4.80% ± 0.80% ） than allograft control group （18.40% ± 1.80% ; P〈0.05） and higher than isograft group （1.20% ± 0.40% ; P〈0.05）. Conclusion： The expression of PCNA in the transplant aorta could be suppressed by atorvastatin, which resalted in relief of chronic rejection of aortic allograft.

Protective Effect of Hydroxysafflor Yellow A on Bleomycin-Induced Pulmonary Inflammation and Fibrosis in Rats

Objective： To observe the effect of hydroxysafflor yellow A （HSYA）, an active ingredient of a traditional Chinese herbal medicine Carthamus tinctorius L., on lung inflammation and pulmonary fibrosis induced by bleomycin （BLM） in rats. Methods： Animals were divided into 6 groups including normal group, model group, three HSYA groups and dexamethasone （DXM） group. Three doses of HSYA （35.6, 53.3, and 80.0 mg？kg–1？day–1） were intraperitoneally （i.p.） injected in rats for 3 weeks after BLM administration and DXM was used as the positive control （n=8 or 12）. Arterial blood gas was assayed and morphological changes were observed. Lung mRNA expressions of tumor necrosis factor （TNF）-α, interleukin （IL）-1β, IL-6 and some cytokines in lung tissue were detected by real-time polymerase chain reaction. Nuclear factor-κB p65 or α-smooth muscle actin （α-SMA） protein distribution in rat lung tissue was observed by immunohistochemistry. Results： On the 7th day after BLM administration, lung tissue showed serious inflammation. Treatment with HSYA or DXM ameliorated lung inflammation. After treatment with HSYA or DXM, oxygen partial pressure （PaO2） increased （HSYA 80.0 mg？kg–1, P〈0.01） and CO2 partial pressure （PaCO2） decreased （HSYA 53.3, 80.0 mg？kg–1, P〈0.05）. Moreover, the mRNA expression of TNF-α, IL-1β, and IL-6; and the number of NF-κB p65 positive cells was lower in HSYA 53.3 and 80.0 mg？kg–1 groups than those in the model group （all P〈0.05）. Twenty-one days after BLM administration, HSYA or DXM treatment ameliorated fibrosis, increased PaO2 （HSYA 53.3, 80.0 mg？kg–1, P〈0.01）, and decreased PaCO2 （53.3 and 80.0 mg？kg–1, P〈0.05）. Further, the mRNA expression of TGF-β1, α-SMA, and collagen Ⅰ as well as the number of α-SMA positive cells increased in the model group and HSYA can attenuate these changes （53.3, 80.0 mg？kg–1, P〈0.05）. Hematoxylin and eosin and Masson＇s trichrome staining indicated that the fibrosis and collagen deposition were ameliorated in HSYA groups （53.3, 80.0 mg？kg–1, P〈0.05）. Conclusion： HSYA could alleviate acute lung inflammation and chronic pulmonary fibrosis induced by BLM in rats.

Effect of Quyu Chencuo Formula(去菀陈莝方)on Renal Fibrosis in Obstructive Nephropathy Rats

Objective: To observe the effect of Quyu Chencuo Formula(去菀陈莝方, QCF) on renal fibrosis in rats with obstructive nephropathy. Methods: Twenty-four rats were randomly divided into three groups, 4 for sham operation as the control group, 10 for unilateral ureteral obstruction(UUO) model group, and the rest 10 for QCF treating UUO model group. All rats were sacrificed under 3% pentobarbital(50 mg/kg) anesthesia on the 14 th day after surgery, then the right kidney samples of rats were harvested for hematoxylin eosin(HE) staining and Masson staining to observe the renal pathological changes. Immunohistochemistry and Western blotting were used to examine the expression of transforming growth factor β1(TGF-β1), and real-time polymerase chain reaction(RT-PCR) was employed to examine the expressions of TGF-β1, α-smooth muscle actin(α-SMA) and E-cadherin mRNA. Results: HE and Masson staining showed that the renal interstitial of the rats in the control group had no significant fibrotic lesion; in the model group, there were obvious interstitial fibrosis; for the QCF group, there were epithelial cell necrosis, infiltration of lymphocytes and mononuclear cells, aggravated interstitial fibrosis in varied degrees, but the pathological changes were less in the QCF group than in the model group. The immunohistochemistry and Western blotting results showed that the TGF-β1 expression was increased significantly in the model group, while decreased significantly in the QCF group(P<0.05); RT-PCR showed that the mRNA expression of α-SMA and TGF-β1 increased significantly in the model group, while both were significantly decreased in the QCF group compared with the model group(P<0.05). The mRNA expression of E-cadherin was decreased significantly in the model group, and it was significantly increased in the QCF group as compared with the model group(P<0.05). Conclusion: QCF may improve renal fibrosis by regulating the expressions of TGF-β1, α-SMA and E-cadherin, and prevent the progress of kidney fibrosis.