Review of current progress in the structure and function of Smad proteins

PURPOSE: To review the recent developments in the structure and function of Smad proteins. DATA SOURCES: Both Chinese- and English-language literatures were searched using MEDLINE/CD-ROM (1997 - 2000) and the Index of Chinese-Language Literature (1997 - 2000). STUDY SELECTION: Data from published articles about TGF-beta signal transduction in recent domestic and foreign literature were selected. DATA EXTRACTION: Data were mainly extracted from 22 articles which are listed in the reference section of this review. RESULTS: Smad proteins mediate signal transduction induced by the TGF-beta superfamily. Based on their structural and functional properties, Smad proteins are divided into three groups. The first group, receptor-regulated Smads (R-Smads), are phosphorylated by activated type I receptors and form heteromeric complexes with the second group of Smads, common mediator Smads (Co-Smads). These Smad complexes translocate into the nucleus to influence gene transcription. Inhibitory Smads (I-Smads) are the third group and these antagonize the activity of R-Smads. In the nucleus, Smads can directly contact Smad-binding elements (SBE) in target gene promoters. Through interaction with different transcription factors, transcriptional co-activators or co-repressors, Smads elicit different effects in various cell types. The aberrance of Smad proteins has been noted in several human disorders such as fibrosis, hypertrophic scarring and cancer. CONCLUSION: The structure of Smads determines their function as transcriptional factors which translocate signals from the cell surface to the nucleus where Smads regulate TGF-beta superfamily-dependent gene expression.

Cross-talk between Smad4 and P38 Proteins in Non-small Cell Lung Cancer

Objective： Impaired signal transduction is associated with tumorigenesis and progression of various kinds of human cancers. Transforming growth factor （TGF）-beta/Smad and ras-mitogen activated protein kinase （MAPK） are two major signal transduction pathways for adjusting cell proliferation and differentiation. Little is known about TGF-beta/Smad4 in non-small cell lung cancer （NSCLC）. Hereby, we investigated the expression of Smad4 in NSCLC, its correlation with MAPK proteins （including p38, ERK1 and JNK1 proteins） and their clinical significance in NSCLC. Methods： The expressions of Smad4, p38, ERK1 and JNK1 were detected at protein level with Western blotting and immunohistochemistry, at transcription level with RT-PCR. Statistical analysis was performed for the comparisons of expressions of Smad4, p38, ERK1 and JNK1, and their correlation with various clinicopathological parameters and the prognosis of NSCLC. Results： The levels of protein and mRNA expression of Smad4 in lung cancer tissues were significantly lower than in normal tissues （P〈0.05）. All these four proteins were associated with TNM staging. There was a strongly negative correlation between p38 and Smad4. Expressions of Smad4, p38 and JNK1, as well as tumor differentiation and staging were significantly correlated with the prognosis of NSCLC by univariate analysis. By multivariate analysis, only Smad4, p38, tumor differentiation and staging were correlated with the prognosis. Taken together, the negative expression of p38 and positive expression of Smad4 were associated with a better prognosis of NSCLC. Conclusion： Smad4 could be of vital importance for the initiation and development of NSCLC. The expression of Smad4 might be inhibited by p38, supporting a cross-talk between main proteins of TGF-beta/Smad and ras-MAPK signal transduction pathways. Smad4 and p38 could be possible prognostic factors for NSCLC.

The Effects of Singal Protein SMADs on Rat Cardiocyte Hypertrophy

Objectives To investigate the role of signal protein SMADs in rat cardiac hypertrophy. Methods The rat models of cardiac hypertrophy were produced by constriction of the abdominal aorta. The left vertricular mass index （LVMI） was investigated. The expression of transforming growth factor-β1 mRNA （TGF-β1） and Smad 2,3,7 mRNA were assessed by RT-PCR. Reslutes The LVMI and the expression of TGF-β1 and Smad 2,3,7mRNA in hypertrophic left ventricule were increased on day 3 after the operation and continued to 4th weeks. The peak expression of TGF-β1 and Smad 2,3 mRNA were in 2 weeks after operation. The expression of Smad 7 was increased in 3 day after operation, but the peak was in 1 week after operation, then decreased. Conclusions The TGF-β1 and signal protein Smad 2,3,7 were included in the progress of rat cardiac hypertrophy produced by constriction of abdominal aorta.

Effect of Tuina along“bladder meridian”alleviating intervertebral disc degeneration by regulating the transforming growth factor-β1/Smad signaling pathway in a rabbit model

OBJECTIVE:The aim of this study was to investigate the protective effects of Tuina(a traditional Chinese massage therapy)on intervertebral disc(IVD)degeneration and the regulatory mechanisms of the transforming growth factor-β1(TGF-β1)/small mothers against decapentaplegic(Smad)signaling pathway.METHODS:Thirty New Zealand white rabbits were randomized into five groups:the control group,model group,model+Tuina group(Tuina group),model+TGF-β1 group(TGF-β1 group),and model+TGF-β1 inhibitor SB431542 group(SB431542 group).The model was established by posterolateral annulus fibrosus puncturing(AFP).Recombinant TGF-β1 and inhibitor SB431542 was injected into the TGF-β1 group and SB431542 group with a microsyringe,respectively.The rabbits in the Tuina group received Tuina treatment along the bladder meridian for 4 weeks.Magnetic resonance imaging(MRI)was performed on rabbits before AFP and after 4 weeks of intervention.Lumbar IVDs(L2-L3 to L4-L5)were harvested after intervention.Histopathological changes in the IVDs were measured by hematoxylin and eosin(HE)staining.Type I collagen was analyzed by immunohistochemistry detection.The expression level of matrix metalloproteinase-3(MMP3)was determined by enzyme-linked immunosorbent assay.Cell apoptosis was evaluated by terminal deoxynucleotidyl transferasemediated nick end labeling and Western blotting.Realtime polymerase chain reaction and Western blotting were used to analyze the expression of TGF-β1 and Smad2/3/4 and a disintegrin and metalloproteinase with thrombospondin motifs 5.RESULTS:Posterolateral AFP induced IVD degeneration in rabbits with histopathological damage and noticeable changes in MRI images.Tuina alleviated histopathological changes and reversed the expression of extracellular matrix degeneration-related molecules and apoptosis-related proteins.Furthermore,AFP induced the activation of TGF-β1 and Smad2/3/4,whereas Tuina therapy markedly reduced the protein expression of Smad2/3 and the gene expression of TGF-β1 and Smad2/3/4.Additionally,the TGF-β1/Smad signaling pathway was activated in the TGF-β1 group,while the TGF-β1/Smad signaling pathway was inhibited in the SB431542 group.CONCLUSION:Posterolateral AFP induced disc degeneration as determined by MRI assessment and histological analysis.Tuina alleviated disc degeneration,possibly by inhibiting the fibrotic response mediated by the TGF-β1/Smad pathway,thus alleviating extracellular matrix degeneration and reducing cell apoptosis.

Acupotomy ameliorates subchondral bone absorption and mechanical properties in rabbits with knee osteoarthritis by regulating bone morphogenetic protein 2-Smad1 pathway

OBJECTIVE:To investigate the effects of acupotomy on the subchondral bone absorption and mechanical properties in rabbits with knee osteoarthritis(KOA).METHODS:The rabbits were divided into blank control,model,acupotomy and electroacupuncture(EA)groups,with 12 rabbits in each.Modified Videman's method was used to prepare KOA model.The acupotomy and EA group were given indicated intervention for 3 weeks.The behavior of rabbits in each group was recorded.Subsequently,cartilage–subchondral bone units were obtained and morphological changes were observed by optical microscope and micro computed tomography.Compression test was used to detect the mechanical properties of subchondral bone,Western blot and real-time polymerase chain reaction(RT-PCR)were applied to detect the expression of bone morphogenetic protein 2-Smad1(BMP2-Smad1)pathway in subchondral bone.RESULTS:Compared with the control group,rabbits in the KOA group showed lameness,knee pain,and cartilage degradation;the subchondral bone showed active resorption,the mechanical properties decreased significantly and the BMP2-Smad1 pathway downregulated significantly.Both acupotomy and EA intervention could increase the thickness of trabecular bone(Tb.Th),the bone volume fraction(BV/TV)and the thickness of subchondral bone plate,reduce the separation of trabecular bone(Tb.Sp),improve the maximum load and elastic modulus of subchondral bone,and effectively delay cartilage degeneration in KOA rabbits.This process may be achieved through upregulation the related proteins of BMP2-Smad1 pathway.The maximum load and elastic modulus of subchondral bone in the acupotomy group were slightly better than those in the EA group.CONCLUSIONS:Acupotomy could effectively protect cartilage by inhibiting abnormal bone resorption and improving mechanical properties of subchondral bone thorough the related proteins of BMP2-Smad1 pathway in KOA rabbits.

Network pharmacology and experimental validation to reveal the pharmacological mechanisms of Sini decoction(四逆汤)against renal fibrosis

OBJECTIVE:To investigate the mechanism by which Sini decoction(四逆汤,SND)improves renal fibrosis(Rf)in rats based on transforming growth factor β1/Smad(TGF-β1/Smad)signaling pathway.METHODS:Network pharmacology was applied to obtain potentially involved signaling pathways in SND's improving effects on Rf.The targets of SND drug components and the targets of Rf were obtained by searching databases,such as the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCSMP)and GeenCard.The intersection targets of two searches were obtained and underwent signaling pathway analysis using a Venn diagram.Then experimental pharmacology was utilized to prove and investigate the effects of SND on target proteins in the TGF-β1/Smad signaling pathway.The Rf rat model was established by unilateral ureteral occlusion(UUO).The expression levels of transforming growth factor,matrix metalloproteinase-9(MMP-9),matrix metal protease-2(MMP-2),connective tissue growth factor(CTGF),and tissue inhibitor of metalloproteinase-1(TIMP-1)were determined by Masson staining of rat renal tissue,and immunohistochemical methods.The expression levels of Smad3,Smad2,and Smad7 in renal tissue were determined by Western blotting(WB).The mechanism of the improving effects of SND on Rf was investigated based on TGF-β1/Smad signaling pathway.RESULTS:A total of 12 drug components of Fuzi(Radix Aconiti Lateralis Preparata),5 drug components of Ganjiang(Rhizoma Zingiber),and 9 drug components of Gancao(Radix Glycy et Rhizoma)were obtained from the database search,and 207 shared targets were found.A total of 1063 Rf targets were found in the database search.According to the Venn diagram,in total,96 intersection targets were found in two database searches.The metabolic pathways involved included TGF-β signaling pathway,phosphatidylinositol-3-kinase/serine-threonine protein kinase signaling(PI3K/Akt)pathway,and hypoxia-inducible factor-1(HIF-1)signaling pathway.Masson staining analysis showed that compared with the model group,the renal interstitial collagen deposition levels in the SSN and SND groups were significantly lower(P<0.05).Immunohistochemical analysis,compared with the control group,the positive cell area expression levels of MMP-9/TIMP-1 and MMP-2/TIMP-1 in the kidney tissue of the model group were significantly decreased(P<0.05,P<0.01),and the positive cell area expression levels of CTGF and TGF-β1 were significantly increased(P<0.01).Compared with the model group,the positive cell area expression levels of MMP-9/TIMP-1 and MMP-2/TIMP-1 in the kidney tissue of the SSN and SND groups were significantly increased(P<0.05,P<0.01),and the positive cell area expression levels of CTGF and TGF-β1 in the kidney tissue were significantly decreased(P<0.05,P<0.01).WB results showed that the SSN group and the SND group could reduce the expression of Smad2 and Smad3(P<0.05)and increase the expression of Smad7(P<0.05).

Shugan Huoxue Huayu Fang(疏肝活血化瘀方)attenuates carbon tetrachloride-induced hepatic fibrosis in rats by inhibiting transforming growth factor-β1/Smad signaling

OBJECTIVE:To investigate the potential mechanism by which Shugan Huoxue Huayu Fang(疏肝活血化瘀方,SGHXHYF)ameliorates liver fibrosis.METHODS:Liver fibrosis was induced in rats by intraperitoneal injection of carbon tetrachloride(CCl_(4))in peanut oil solution(40%,3 m L/kg body weight)twice a week for 8 weeks.A normal control group received the same volume of peanut oil alone.During weeks 5-8,the CCl_(4)-injected rat groups were administered saline(vehicle control),colchicine(0.1 mg/mL,1 mg/kg,positive control),or SGHXHYF(0.1 mg/mL;0.3,0.6 and 1.2 mg/kg)once daily by oral gavage.Rats were sacrificed 24 h after the last treatment.Blood samples were collected for measurement of serum alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),albumin(ALB),collagenⅠ,and collagenⅢlevels.Liver samples were analyzed by histopathological staining,Masson's staining of extracellular matrix proteins,and immune-ohistochemical staining ofα-smooth muscle actin(α-SMA).TGF-β1/Smad protein and mRNA levels were analyzed by Western blot and quantitative reverse transcription-polymerase chain reaction analysis,respectively.In vitro experiments were also performed using rat hepatic stellate cells(HSCs).RESULTS:Compared with the control animals,CCl_(4)-exposed rats exhibited elevated serum levels of ALT,AST,ALP,collagenⅠ,and collagenⅢ;reduced serum levels of ALB;and increased collagen deposition andα-SMA expression in liver sections,reflecting liver fibrosis.CCl_(4) also increased expression of TGF-β1 and the activated(phosphorylated)forms of Smad2 and Smad3 but reduced expression of the negative regulator Smad7 in the liver.Notably,concomitant administration of SGHXHYF to CCl_(4)-exposed rats was found to significantly reverse or abolish the pro-fibrotic effects of CCl_(4) in the liver and reduced serum transferase levels.Analysis of HSCs in vitro confirmed that,mechanistically,SGHXHYF inhibited activation of the TGF-β1/Smad signaling pathway by downregulating phosphorylated Smad2 and Smad3 and upregulating Smad7 levels.CONCLUSION:SGHXHYF ameliorated CCl_(4)-induced liver fibrosis by inhibiting the TGF-β1/Smad signaling pathway.These findings suggest that SGHXHYF may have clinical utility for the treatment or prevention of liver fibrosis.

Danggui Buxue Tang ameliorates bleomycin-induced pulmonary fibrosis in rats through inhibiting transforming growth factor-β1/Smad3/plasminogen activator inhibitor-1 signaling pathway

OBJECTIVE: To investigate the effect of Danggui Buxue Tang(DBT), a decoction from Traditional Chinese Medicine, on bleomycin-induced pulmonary fibrosis in rats, and to propose the possible underlying mechanism.METHODS: Forty male Sprague-Dawley rats were randomly divided into sham group, model group,prednisone group and DBT group. Pulmonary fibrosis rat model was established by intratracheal injection with bleomycin. Body weight and lung index were monitored. Histopathologic examination and collagen deposition were determined using Hematoxylin and eosin(HE) and Masson's trichrome staining. Immunohistochemistry staining was applied to observe the expression of alpha-smooth muscle actin(α-SMA). m RNA expression of α-SMA,collagen Ⅰ and collagen Ⅲ were measured by realtime fluorescence quantitative PCR(RT-q PCR). Inflammatory cytokines, including tumor necrosis factor alpha(TNF-α), interleukin-6(IL-6) and IL-1β in serum were detected by Enzyme-linked immunosorbent assay. Alkali hydrolysis method was conducted to investigate the content of hydroxyproline(HYP). Transforming growth factor-β1(TGF-β1),Smad3 and plasminogen activator inhibitor-1(PAI-1) protein level were examined by Western blot assay.RESULTS: DBT significantly reduced the severity of bleomycin-induced pulmonary fibrosis and inflammation as indicated by minimizing the lost of weight, and by lowering the levels of lung index, inflammation score, Ashcroft score, collagen volume fraction(%), HYP, α-SMA, collagen Ⅰ, collagen Ⅲ,TNF-α, IL-6, IL-1β, TGF-β1, Smad3 and PAI-1, consistent with the effect of prednisone.CONCLUSION: Our findings suggest that DBT is able to ameliorate the pulmonary fibrosis, the possible mechanism may involve inhibition of pulmonary inflammation and collagen deposition, possibly via suppressing TGF-β1/Smad3/PAI-1 signaling pathway.

Efficacy of Danggui Buxue decoction(当归补血汤)on diabetic nephropathy-induced renal fibrosis in rats and possible mechanism

OBJECTIVE:To observe the efficacy of Danggui Buxue decoction(当归补血汤,DBD) on diabetic nephropathyinduced renal fibrosis in rats,and to study the possible mechanism.METHODS:Sixty male Goto Kakizaki(GK) rats were randomly assigned to the model group,gliquidone group,astragaloside Ⅳ group,and high-,medium-and lowdoses DBD groups.After 8 weeks,changes in body weight,blood glucose,serum creatinine,serum urea nitrogen,and total cholesterol were observed.Changes in transforming growth factor-β1(TGF-β1),Smad3,and Smad5 pathways and the expression of the fibrosisrelated proteins collagen Ⅳ(col Ⅳ),α-smooth muscle actin(α-SMA),and vimentin were assessed.The degree of renal fibrosis was observed by immunohistochemistry and Mason staining.The expression of interleukin 6(IL-6),interleukin 10(IL-10),tumor necrosis factor(TNF-α),and C-reactive protein(CRP) in the kidneys was assessed using enzyme linked immunosorbent assay.RESULTS:Our experiments showed that DBD effectively reduced blood glucose,blood urea nitrogen,and creatinine levels after 8 weeks of administration,improved renal function in diabetic rats,alleviated renal fibrosis,and reduced the renal tissue levels of IL-6,IL-10,TNF-α,and CRP.Furthermore,DBD decreased the expression of TGF-β1,Smad3,col IV,α-SMA,and vimentin in renal tissues and increased the expression of Smad5.CONCLUSIONS:DBD ameliorates diabetic renal interstitial fibrosis by modulating the TGF-β1/Smads pathway.

Moxibustion enables protective effects on rheumatoid arthritis-induced myocardial injury via transforming growth factor beta1 signaling and metabolic reprogramming

OBJECTIVE:To examine the effects of moxibustion on myocardial injury and myocardial metabolomics in rats with rheumatoid arthritis(RA)based on the transforming growth factor beta1(TGF-β1)/Smads signaling pathway.METHODS:One hundred rats were treated with saline[normal control(NC)group]or complete Freund’s adjuvant(CFA)by right plantar injection for the RA model group,and the latter were randomly divided into 4 groups.Tripterygium wilfordii polyglycoside tablets(雷公藤多苷片,TPT)have anti-inflammatory and are widely used in the clinical treatment of RA,therefore serving as a positive control group.Three days post injection rats were given TPT tablet(TPT group),acupuncture therapy(APT group),and moxibustion treatment(MOX group)for 15 consecutive days,while NC group and model group were equally grasped and fixed and received normal saline.Rat joint swelling scores and arthritis index(AI)were evaluated in each group before the CFA challenge,therapy and after receiving therapy.Myocardial ultrastructure was observed by electron microscope.Enzyme-linked immunosorbent assay was used to detect cardiac troponin I(cTnI)levels in rat myocardial tissue.Quantitative reverse transcription polymerase chain reaction and Western blotting analysis were used to measure the mRNA and protein levels of TGF-βsignaling molecules including TGF-β1,Smad2,Smad3,Smad4,and Smad7.Myocardial metabolomics was analyzed using gas chromatography-mass spectrometer.RESULTS:Compared with model group,RA model rats receiving TPT,acupuncture,or moxibustion therapy all showed reduced joint swelling scores and AI(all P<0.01)and improved myocardial damage,whereas rats treated with moxibustion were found to be more marked.Consistently,the expressions of cTnI,TGF-β1,Smad2,Smad3,and Smad4 were found to be elevated in model rat group in contrast to NC rats and were significantly downregulated in TPT,APT and MOX group when compared with model group,while the levels of Smad7 showed the opposite result(all P<0.01).Moreover,the dissection of metabolomics suggested a novel metabolite biomarker panel including D-Xylulose 5-phosphate,dihydroxyacetone phosphate,arachidonic acid,etc was defined and implicated in amino acid,glucose,and fatty acid metabolic processes as revealed by principal component analysis and partial least squares discriminant analysis.CONCLUSION:Moxibustion prevents RA-induced inflammatory response and offers potent therapeutic effects on myocardial dysfunctions.The protective effects might be associated with its role in TGF-β1 inactivation and metabolic reprogramming.

Uncovering pharmacological mechanisms of Phellinus linteus on focal segmental glomeruloscleosis rats through tandem mass tag-based quantitative proteomic analysis,network pharmacology analysis and experimental validation

OBJECTIVE:To explore the underlying molecular mechanism of Phellinus linteus(P.linteus).METHODS:We used a tandem mass tag-based quantitative proteomic method to determine the differentially expressed proteins.Network pharmacology analysis was used to analysis the main components of P.linteus and construct the compound-target network.Western blotting and quantitative real-time polymerase chain reaction(qRT-PCR)were used to validate the analyses results.RESULTS:The expression levels of thrombospondin-1(TSP-1)and transforming growth factor(TGF)-β1/Smad3 signaling pathway proteins were significantly upregulated in focal segmental glomeruloscleosis(FSGS)rats.The P.linteus reduced the expression levels of TSP-1 and TGF-β1 signaling pathway proteins.Network pharmacology analysis revealed that protocatechualdehyde was the main active component.Subsequent in vivo and in vitro experiments validated the results of proteomic and network pharmacology analyses.CONCLUSIONS:Our results suggested that P.linteus may inhibit renal sclerosis by inhibiting TSP-1-activated TGF-β1 signaling and may have potential applications in the treatment of FSGS.

Shenweifang-containing serum inhibits transforming growth factor-β1–induced myofibroblast differentiation in normal rat kidney interstitial fibroblast cells

OBJECTIVE:To investigate the efficacy of Shenweifang(SWF)-containing serum on transforming growth factor(TGF)-β1–induced fibroblast-myofibroblast transition in normal rat kidney interstitial fibroblast cells(NRK-49 F).METHODS:Sprague-Dawley rats were gavaged with one of five solutions:(a)saline;(b)saline plus low-dose SWF;(c)saline plus medium-dose SWF;(d)saline plus highdose SWF;and(e)saline plus valsartan.NRK-49 F cells were treated with TGF-β1 and cultured using serum from the gavaged rats.RESULTS:TGF-β1 treatment increased the expression ofα-smooth muscle actin,proliferating cell nuclear antigen,collagenⅠ,Smad3,mitogen-activated protein kinase(MAPK)10,and c-Jun N-terminal kinase(JNK)3 and induced abnormalities in cell morphology,cell cycle progression,and cell proliferation.CONCLUSIONS:SWF-or valsartan-containing serum corrected(or partially corrected)TGF-β1–induced abnormal changes in this in vitro system.SWF-containing serum reversed abnormalities in morphology,cell cycle progression,and proliferation in TGF-β1–treated NRK-49F cells,probably by blocking the TGF-β1/Smads and TGF-β1/MAPK/JNK pathways.

Effects of insulin-like growth factor binding protein-related protein 1 in mice with hepatic fibrosis induced by thioacetamide

Background Insulin-like growth factor binding protein-related protein 1 （IGFBPrP1） can activate hepatic stellate cells and increase extracellular matrix （ECM） in vitro. However, the effects of IGFBPrP1 in mice with hepatic fibrosis, and the mechanisms of these effects, are currently unknown. We aim to address these issues in this study. Methods Intraperitoneal injection of thioacetamide （TAA） is a classic method for establishing a mouse model of hepatic fibrosis. Using this model, we administered anti-IGFBPrP1 antibody, again via intraperitoneal injection. The morphological changes of liver fibrosis were observed with both HE and Masson stainning. The immunohistochemical assays and Western blotting were used to measure changes in IGFBPrP1, a-smooth muscle actin （a-SMA） and ECM in liver tissues, and the expression of transforming growth factor-β1 （TGF-β1） and Smad3. Data were statistically analyzed using one-way analysis of variance （ANOVA）, the SNK-q test for inter-group differences. Results The Masson staining analysis showed that compared with normal control group, content of collagen fiber in TAA5w group was significantly increased （P 〈0.01）, and it was significantly decreased in TAA5w/alGFBPrP1 group compared with in TAA5w group （P 〈0.01）. The expression of hepatic IGFBPrP1, a-SMA, TGF-β1, Smad3, collagen 1 and fibronectin （FN） was significantly up-regulated in the TAA5w group （P 〈0.01）. Anti-IGFBPrP1 treatment reversed these changes （P 〈0.01）. Conclusions IGFBPrP1 plays an important role in the development of hepatic fibrosis. Anti-IGFBPrP1 prevents fibrosis in mice by suppressing the activation of hepatic stellate cells, inhibiting the synthesis of major components of the ECM （namely, collagen I and FN）. The mechanism for this suppression of fibrosis is associated with the TGF-β1/Smad3 signaling pathways.

Ultra-highly diluted plant extracts of Hydrastis canadensis and Marsdenia condurango induce epigenetic modifications and alter gene expression profiles in HeLa cells in vitro

OBJECTIVE： Methylation-specific epigenetic process and gene expression profiles of HeLa cells treated with ultra-high dilutions （HDs） of two plant extracts, Hydrastis canadensis （HC-30） and Marsdenia condurango （Condu-30）, diluted 106o times, were analyzed against placebo 30C （PI-30） for alterations in gene profiles linked to epigenetic modifications. METHODS： Separate groups of cells were subjected to treatment of Condu-30, HC-30, and PI- 30 prepared by serial dilutions and succussions. Global microarray data recorded on Affymetrix platform, using 25-mer probes were provided by iLifeDiscoveries, India. Slides were scanned with 3000 7G microarray scanner and raw data sets were extracted from Cel （raw intensity） files. Analyses of global microarray data profile, differential gene expression, fold change and clusters were made using GeneSpring GX12.5 software and standard normalization procedure. Before microarray study, concentration of RNA （ng/IJL）, RIN value and rRNA ratio for all the samples were analysed by Agilant Bioanalyzer 2100. Reverse transcriptase polymerase chain reaction （RT-PCR） and quantitative RT- PCR were done for analyzing SMAD-4 expression. Fluorescence-activated cell sorting study was further made to elucidate fate of cells at divisional stages. Methylation-specific restriction enzyme assay was conducted for ascertaining methylation status of DNA at specific sites. RESULTS： HDs of HC-30 and Condu-30 differentially altered methylation in specific regions of DNA and expression profiles of certain genes linked to carcinogenesis, as compared to PI-30. Two separate cut sites were found in genomic DNA of untreated and placebo-treated HeLa cells when digested with McrBC, compared to a single cut observed in Condu-30-treated genomic DNA. SMAD-4 gene expression validated the expression pattern observed in microarray profile. Methylation-specific restriction enzyme assay elucidated differential epigenetic modifications in drug-treated and control cells. CONCLUSION： HDs triggered epigenetic modifications and alterations in microarray gene expression profiles of many genes associated with carcinogenesis in HeLa cells in vitro.