Dihydroergotamine ameliorates liver fibrosis by targeting transforming growth factor β type Ⅱ receptor

BACKGROUND The transforming growth factor β(TGFβ) signaling pathway plays a crucial role in the development of liver fibrosis by activating TGFβ type Ⅱ receptor(TGFβR2), followed by the recruitment of TGFβR1 finally triggering downstream signaling pathway.AIM To find drugs targeting TGFβR2 that inhibit TGFβR1/TGFβR2 complex formation, theoretically inhibit TGFβ signaling pathway, and thereby ameliorate liver fibrosis.METHODS Food and Drug Administration-approved drugs were screened for binding affinity with TGFβR2 by virtual molecular docking. We identified 6 candidates and further explored their potential by Cell Counting Kit-8(CCK-8) cell cytotoxic experiment to validate toxicity and titrated the best cellular working concentrations. Next, we further demonstrated the detailed molecular working mechanisms using mutagenesis analysis. Finally, we used a mouse model to investigate its potential anti-liver fibrosis effect.RESULTS We identified 6 drug candidates. Among these 6 drugs, dihydroergotamine(DHE) shows great ability in reducing fibrotic gene expressions such as collagen, p-SMAD3, and α-SMA in TGFβ induced cellular model of liver fibrosis in LX-2 cells. Furthermore, we demonstrated that DHE binds to TGFβR2. Moreover, mutation of Leu27, Phe30, Thr51, Ser52, Ile53, and Glu55 of TGFβR2 disrupted the binding of TGFβR2 with DHE. In addition, DHE significantly improved liver fibrosis, as evidenced by Masson’s trichrome staining of liver sections. This is further supported by the width and the velocity of the portal vein, and serum markers of liver function. In line with those observations, DHE also decreased macrophages infiltration and extracellular matrix deposition in the liver.CONCLUSION DHE alleviates liver fibrosis by binding to TGFβR2 thereby suppressing TGFβ signaling pathway. We show here that as far as drug repurposing, DHE has great potential to treat liver fibrosis.

miR-34a mediates oxaliplatin resistance of colorectal cancer cells by inhibiting macroautophagy via transforming growth factor-β/Smad4 pathway

To investigate whether microRNA (miR)-34a mediates oxaliplatin (OXA) resistance of colorectal cancer (CRC) cells by inhibiting macroautophagy via the transforming growth factor (TGF)-β/Smad4 pathway.METHODSmiR-34a expression levels were detected in CRC tissues and CRC cell lines by quantitative real-time polymerase chain reaction. Computational search, functional luciferase assay and western blotting were used to demonstrate the downstream target of miR-34a in CRC cells. Cell viability was measured with Cell Counting Kit-8. Apoptosis and macroautophagy of CRC cells were analyzed by flow cytometry and transmission electron microscopy, and expression of beclin I and LC3-II was detected by western blotting.RESULTSExpression of miR-34a was significantly reduced while expression of TGF-β and Smad4 was increased in CRC patients treated with OXA-based chemotherapy. OXA treatment also resulted in decreased miR-34a levels and increased TGF-β and Smad4 levels in both parental cells and the OXA-resistant CRC cells. Activation of macroautophagy contributed to OXA resistance in CRC cells. Expression levels of Smad4 and miR-34a in CRC patients had a significant inverse correlation and overexpressing miR-34a inhibited macroautophagy activation by directly targeting Smad4 through the TGF-β/Smad4 pathway. OXA-induced downregulation of miR-34a and increased drug resistance by activating macroautophagy in CRC cells.CONCLUSIONmiR-34a mediates OXA resistance of CRC by inhibiting macroautophagy via the TGF-β/Smad4 pathway.

Targeting key signalling pathways in oesophageal adenocarcinoma:A reality for personalised medicine?

Cancer treatments are rapidly changing.Curative treatment for oesophageal adenocarcinoma currently involves surgery and cytotoxic chemotherapy or chemoradiotherapy.Outcomes for both regimes are generally poor as a result of tumor recurrence.We have reviewed the key signalling pathways associated with oesophageal adenocarcinomas and discussed the recent trials of novel agents that attempt to target these pathways.There are many trials underway with the aim of improving survival in oesophageal cancer.Currently,phase 2 and 3 trials are focused on MAP kinase inhibition,either through inhibition of growth factor receptors or signal transducer proteins.In order to avoid tumor resistance,it appears to be clear that targeted therapy will be needed to combat the multiple signalling pathways that are in operation in oesophageal adenocarcinomas.This may be achievable in the future with the advent of gene signatures and a combinatorial approach.

Feedback regulation between phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1 and transforming growth factor β1 and prognostic value in gastric cancer

BACKGROUND Phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1(PREX1)was reported to be overexpressed in some cancers and involved in cancer development,but its expression and significance in gastric cancer remain unclear.AIM To evaluate the expression of PREX1 in gastric cancer and its significance in the development of gastric cancer,especially to evaluate the potential mechanism of PREX1 in gastric cancer.METHODS Bioinformatic analysis was performed in order to examine the expression of PREX1 in gastric cancer.The relationship between the survival rate of gastric cancer patients and PREX1 expression was assessed by Kaplan Meier portal.The Gene Set Enrichment Analysis and the correlation between PREX1 and transforming growth factor(TGF)β1 pathway-related mediators were evaluated by cBioPortal for Cancer Genomics.Western blotting and reverse transcriptase polymerase chain reaction assay were used to test the role of TGFβ1 on the expression of PREX1.Western blotting and dual-luciferase reporter system was used to evaluate the effect of PREX1 on the activation of TGFβ1 pathway.Wound healing and Transwell assay were used to assess the effect of PREX1 on the metastasis activity of gastric cancer cells.RESULTS PREX1 was overexpressed in the gastric tumors,and the expression levels were positively associated with the development of gastric cancer.Also,the high expression of PREX1 revealed poor prognosis,especially for those advanced and specific intestinal gastric cancer patients.PREX1 was closely involved in the positive regulation of cell adhesion and positively correlated with TGFβ1-related mediators.Furthermore,TGFβ1 could induce the expression of PREX1 at both the protein and mRNA level.Also,PREX1 could activate the TGFβ1 pathway.The induced PREX1 could increase the migration and invasion activity of gastric cancer cells.CONCLUSION PREX1 is overexpressed in gastric cancer,and the high level of PREX1 predicts poor prognosis.PREX1 is closely associated with TGFβsignaling and promotes the metastasis of gastric cancer cells.

Spatial signalling mediated by the transforming growth factor-β signalling pathway during tooth formation

Tooth development relies on sequential and reciprocal interactions between the epithelial and mesenchymal tissues, and it is continuously regulated by a variety of conserved and specific temporal-spatial signalling pathways. It is well known that suspensions of tooth germ cells can form tooth-like structures after losing the positional information provided by the epithelial and mesenchymal tissues. However, the particular stage in which the tooth germ cells start to form tooth-like structures after losing their positional information remains unclear. In this study, we investigated the reassociation of tooth germ cells suspension from different morphological stages during tooth development and the phosphorylation of Smad2/3 in this process. Four tooth morphological stages were designed in this study. The results showed that tooth germ cells formed odontogenic tissue at embryonic day （E） 14.5, which is referred to as the cap stage, and they formed tooth-like structures at E16.5, which is referred to as the early bell stage, and E18.5, which is referred to as the late bell stage. Moreover, the transforming growth factor-β signalling pathway might play a role in this process.

Nanoscale materials transformations revealed by liquid phase TEM

Nanoscale materials often undergo structural,morphological,or chemical changes,especially in solution processes,where heterogeneity and defects may significantly impact the transformation pathways.Liquid phase transmission electron microscopy(TEM),allowing us to track dynamic transformations of individual nanoparticles,has become a powerful platform to reveal nanoscale materials transformation pathways and address challenging issues that are hard to approach by other methods.With the development of modern liquid cells,implementing advanced imaging and image analysis methods,and strategically exploring diverse systems,significant advances have been made in liquid phase TEM,including improved high-resolution imaging through liquids at the atomic level and remarkable capabilities in handling complex systems and reactions.In the past more than a decade,we spent much effort in developing and applying liquid phase TEM to elucidate how atomic level heterogeneity and defects impact various physicochemical processes in liquids,such as growth,self-assembly of nanoparticles,etching/corrosion,electrodeposition of alkali metals,catalyst restructuring during reactions,and so on.This article provides a brief review of the liquid phase TEM study of nanoscale materials transformations,focusing on the growth of nanomaterials with distinct shape/hierarchical structures,such as one-dimensional(1D)growth by nanoparticle attachment,two-dimensional(2D)growth with nanoparticles as intermediates,core-shell structure ripening,solid-liquid interfaces including those in batteries and electrocatalysis,highlighting the impacts of heterogeneity and defects on broad nanoscale transformation pathways.

Association of overexpression of TIF1γ with colorectal carcinogenesis and advanced colorectal adenocarcinoma

AIM:To determine the expression and clinical significance of transcriptional intermediary factor 1 gamma (TIF1γ),Smad4 and transforming growth factor-beta (TGFβR) across a spectrum representing colorectal cancer (CRC) development.METHODS:Tissue microarrays were prepared from archival paraffin embedded tissue,including 51 colorectal carcinomas,25 tubular adenomas (TA) and 26 HPs,each with matched normal colonic epithelium.Immunohistochemistry was performed using antibodies against TIF1γ,Smad4 and TGFβ RⅡ.The levels of expression were scored semi-quantitatively (score 0-3 or loss and retention for Smad4).RESULTS:Overexpression of TIF1γ was detected in 5/26 (19%) HP;however,it was seen in a significantly higher proportion of neoplasms,15/25 (60%) TAs and 24/51 (47%) CRCs (P<0.05).Normal colonic mucosa,HP,and TAs showed strong Smad4 expression,while its expression was absent in 22/51 (43%) CRCs.Over-expression of TGFβ RⅡ was more commonly seen in neoplasms,13/25 (52%) TAs and 29/51 (57%) CRCs compared to 9/26 (35%) HP (P<0.05).Furthermore,there was a correlation between TIF1γ overexpression and Smad4 loss in CRC (Kendall tau rank correlation value=0.35,P<0.05).The levels of TIF1γ overexpression were significantly higher in stage Ⅲ than in stage Ⅰ and Ⅱ CRC (P<0.05).CONCLUSION:The findings suggest that over-expression of TIF1γ occurs in early stages of colorectal carcinogenesis,is inversely related with Smad4 loss,and may be a prognostic indicator for poor outcome.

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.

Role of activin receptor-like kinase 1 in vascular development and cerebrovascular diseases

Activin receptor-like kinase 1(ALK1)is a transmembrane serine/threonine receptor kinase of the transforming growth factor beta(TGFβ)receptor superfamily.ALK1 is specifically expressed in vascular endothelial cells,and its dynamic changes are closely related to the proliferation of endothelial cells,the recruitment of pericytes to blood vessels,and functional differentiation during embryonic vascular development.The pathophysiology of many cerebrovascular diseases is today understood as a disorder of endothelial cell function and an imbalance in the proportion of vascular cells.Indeed,mutations in ALK1 and its co-receptor endoglin are major genetic risk factors for vascular arteriovenous malformation.Many studies have shown that ALK1 is closely related to the development of cerebral aneurysms,arteriovenous malformations,and cerebral atherosclerosis.In this review,we describe the various roles of ALK1 in the regulation of angiogenesis and in the maintenance of cerebral vascular homeostasis,and we discuss its relationship to functional dysregulation in cerebrovascular diseases.This review should provide new perspectives for basic research on cerebrovascular diseases and offer more effective targets and strategies for clinical diagnosis,treatment,and prevention.

Toward sustainable food systems: global initiatives and innovations

A recent UN Sustainable Development Goals(SDGs) analysis indicated a significant regression in the global SDG goal scores, particularly in SDG 2—Zero Hunger. The emissions of environmental pollution caused by meeting food demands have prompted some countries to intensify their climate change mitigation efforts. These circumstances have introduced significant uncertainty to the future global sustainable food development. Additionally, a notable global challenge is the persistence of hidden hunger, primarily characterized by the insufficient consumption of high-quality animal protein. Addressing this issue would necessitate increased environmental costs to attain high-quality food security. The future food system presents a significant challenge in coordinating food security, food quality and environmental quality. This article presents a comprehensive review and proposes a three-step strategy for future agricultural development based on food security, quality, and environmental aspects. This is a novel food system transfer strategy, as it concurrently addresses both global food security and environmental thresholds. It involves the construction of an efficient food system that operates within the constraints of environmental limits. The objective is to align with global SDG indicators and to maintain natural resource consumption and pollutant emissions within planetary boundaries.

Oxidation of diclofenac by birnessite: Identification of products and proposed transformation pathway

Diclofenac(DCF), a widely used non-steroidal anti-inflammatory, reacted readily with birnessite under mild conditions, and the pseudo first order kinetic constants achieved 8.84 × 10^-2 hr^-1. Five products of DCF including an iminoquinone product(2,5-iminoquinone-diclofenac) and four dimer products were observed and identified by tandem mass spectrometry during the reaction. Meanwhile, 2,5-iminoquinone-diclofenac was identified to be the major product, accounting for 83.09% of the transformed DCF. According to the results of spectroscopic Mn(III) trapping experiments and X-ray Photoelectron Spectroscopy, Mn(IV) contained in birnessite solid was consumed and mainly converted into Mn(III) during reaction process, which proved that the removal of DCF by birnessite was through oxidation. Based on the identified products of DCF and the changes of Mn valence state in birnessite solid, a tentative transformation pathway of DCF was proposed.

Effect of ursodeoxycholic acid on TGF betal/Smad signaling pathway in rat hepatic stellate cells

Background Hepatic fibrosis is the key stage of the pathological progress from hepatic injury to cirrhosis. Ursodeoxycholic acid （UDCA） has been known as having significant clinical therapeutic effects on chronic liver diseases. Our research aimed to study the effect of UDCA on the signaling pathway of transforming growth factor beta1 （TGFβ1）/Smad and discuss its possible molecular mechanisms of inhibiting hepatic fibrosis. Methods Rat hepatic stellate cells were cultured in vitro and randomly assigned to 4 groups. Group A was control group with only DMEM culture medium applied, and groups B, C, D were experimental groups, with different doses of UDCA （1.0 mmol/L, 0.5 mmol/L and 0.25 mmol/L respectively） added into their DMEM culture medium for further culture of 24 hours and 48 hours. The protein expressions of TGFβ1, TGF type 1 receptor, Smad3, Smad4 and Smad7 were measured by Western blotting, as well as the expressions of TGFβ1, Smad3, Smad7 and cAMP response element （CREB） binding protein （CBP） mRNA by real-time PCR. SPSS 11.5 statistical package was adopted for data analyses. Results Compared with control group, the mRNA expressions of TGFβ1 in the high and middle UDCA dose groups for 24 hours and 48 hours significantly decreased （P 〈0.05）, the protein expressions of TGFβ1 in the two above groups for 48 hours and in the high dose group for 24 hours significantly decreased （P 〈0.05）. The protein and mRNA expressions of Smad3 in each UDCA dose group for 24 hours and 48 hours significantly decreased, with significant difference among different UDCA dose groups and between that of 24 hours and 48 hours observed （P 〈0.05）. The protein and mRNA expressions of Smad7 in the high and middle UDCA dose groups for 24 hours and 48 hours significantly increased. The CBP mRNA expression in each UDCA dose group for 24 hours and 48 hours significantly decreased （P 〈0.05）, with significant difference among different UDCA dose groups observed （P 〈0.05）. Conclusion UDCA could curb the development of hepatic fibrosis through affecting the signaling pathway of TGFβ1/Smad by inhibiting the expressions of TGFβ1, Smad3 and CBP and increasing the expression of Smad7.

Qingxuan Jiangya Decoction(清眩降压汤) Prevents Blood Pressure Elevation and Ameliorates Vascular Structural Remodeling via Modulating TGF-β 1/Smad Pathway in Spontaneously Hypertensive Rats

Objective:To elevate the effects of Qingxuan Jiangya Decoction(清眩降压汤,QXJYD)on hypertension and vascular structural remodeling(VSR)in spontaneously hypertensive rats(SHRs),and investigate the underlying mechanisms.Methods:SHRs(n=8)were given intra-gastric administration with 60 mg/kg of QXJYD or saline,daily for 8 weeks,while rats in SHR-control(n=8)and WKY(n=8)groups were received equal volumes of saline solution.Systolic blood pressures(SBP),diastolic blood pressures(DBP)and mean blood pressures(MBP)were measured once a week.The levels of angiotensinⅡ(AngⅡ),endothelin 1(ET-1)and plasma renin activity(PRA)were tested by enzyme-linked immunosorbent assay(ELISA)and radioimmunoassay,respectively.The effect of QXJYD on VSR was determined by examining the media thickness and the ex vivo contractility of thoracic aortic.The proliferation and fibrosis of vascular smooth muscle cells(VSMCs)were examined via immunohistochemical(IHC)staining for proliferating cell nuclear antigen(PCNA),collagen Ⅰ and collagen Ⅲ,respectively.The mRNA and protein expressions of transforming growth factor β1(TGF-β1),Smad3 and phosphorylation of Smad3 in thoracic aorta tissues were determined by real-time polymerase chain reaction(PCR)and Western blot assay,respectively.Results:QXJYD treatment led to a significant decrease of the elevation of blood pressure in SHRs and reduced the levels of AngⅡ,ET-1 and PRA in the serum(P<0.05).In addition,QXJYD treatment remarkably ameliorated VSR and vascular function in SHRs.Moreover,QXJYD inhibited VSMC proliferation and fibrosis by suppressing the expression of PCNA,collagen Ⅰ and collagen Ⅲ in thoracic aortic.Furthermore,QXJYD inhibited the expression of TGF-β1,Smad3 and the phosphorylation of Smad3,respectively(P<0.05).Conclusion:QXJYD reversed VSR by inhibiting VSMC proliferation and collagen deposition via regulation of TGF-β1/Smad signaling pathway,which may,in part,illuminate its anti-hypertensive activities.

Acupuncture and Moxibustion Inhibited Intestinal Epithelial-Mesenchymal Transition in Patients with Crohn's Disease Induced by TGF-β1/Smad3/Snail Pathway:A Clinical Trial Study

Objective:To explore whether acupuncture combined with moxibustion could inhibit epithelialmesenchymal transition in Crohn’s disease by affecting the transforming growth factorβ1(TGF-β1)/Smad3/Snail pathway.Methods:Sixty-three patients with Crohn’s disease were randomly divided into an observation group(31 cases)receiving moxibustion at 43℃ combined with acupuncture,and a control group(32 cases)receiving moxibustion at 37℃combined with sham acupuncture using a random number table.Patients were treated for12 weeks.Crohn’s Disease Activity Index(CDAI)was used to evaluate disease activity.Hematoxylin-eosin staining and transmission electron microscopy were utilized to observe the morphological and ultrastructural changes.Immunohistochemistry was used to detect the expression of transforming growth factorβ1(TGF-β1),TβR1,TβR2,Smad3,Snail,E-cadherin and fibronectin in intestinal mucosal tissues.Results:The decrease of the CDAI score,morphological and ultrastructural changes were more significant in observation group.The expression levels of TGF-β1,TβR2,Smad3,and Snail in the observation group were significantly lower than those before the treatment(P<0.05 or P<0.01).After treatment,the expression levels of TGF-β1,TβR2,and Snail in the observation group were significantly lower than those in the control group(all P<0.05);compared with the control group,the expression of fibronectin in the observation group was significantly decreased,and the expression of E-cadherin was significantly increased(all P<0.05).Conclusions:Moxibustion at 43℃combined with acupuncture may suppress TGF-β1/Smad3/Snail pathway-mediated epithelial-mesenchymal transition of intestinal epithelial cells in Crohn’s disease patients by inhibiting the expression levels of TGF-β1,TβR2,Smad3,and Snail.(Registration No.ChiCTR-IIR-16007751).

Chlorination of para-substituted phenols:Formation of α, β-unsaturated C4-dialdehydes and C4-dicarboxylic acids

Despite the widespread occurrence of phenols in anthropogenic and natural compounds, their fate in reactions with hypochlorous acid(HOCl), one of the most common water treatment disinfectants, remains incompletely understood. To close this knowledge gap, this study investigated the formation of disinfection by-products(DBPs) in the reaction of free chlorine with seven para-substituted phenols. Based on the chemical structures of the DBPs and the reaction mechanisms leading to their formation, the DBPs were categorized into four groups: chlorophenols, coupling products, substituent reaction products, and ring cleavage products. In contrast to previous studies that investigated the formation of earlystage chlorophenols, the primary focus of this study was on the elucidation of novel ring cleavage products, in particular α, β-unsaturated C-dialdehydes, and C-dicarboxylic acids, which, for the first time, were identified and quantified in this study. The molar yields of 2-butene-1,4-dial(BDA), one of the identified α, β-unsaturated C-dialdehydes, varied among the different phenolic compounds, reaching a maximum value of 10.4% for bisphenol S. Molar yields of 2-chloromaleic acid(Cl-MA), one of the identified C-dicarboxylic acids, reached a maximum value of 30.5% for 4-hydroxy-phenylacetic acid under given conditions. 2,4,6-trichlorophenol(TCP) was shown to be an important intermediate of the parent phenols and the C-ring cleavage products. Based on the temporal trends of α, β-unsaturated C-dialdehydes and C-dicarboxylic acids, their formation is likely attributable to two separate ring cleavage pathways. Based on the obtained results, an overall transformation pathway for the reaction of para-substituted phenols with free chlorine leading to the formation of novel Cring cleavage products was proposed.

Xueshuantong for Injection(Lyophilized,注射用血栓通)Alleviates Streptozotocin-Induced Diabetic Retinopathy in Rats

Objective To investigate the ameliorate effect and underlying mechanism of Xueshuantong for Injection(Lyophilized,注射用血栓通,XST)in streptozocin(STZ)-induced diabetic retinopathy(DR)rats.Methods Diabetes mellitus(DM)model was induced by intraperitoneal(i.p.)injection of STZ(60 mg/kg)in Sprague-Dawley rats.Diabetic rats were randomized into 3 groups(n=10)according to a random number table,including DM,XST50 and XST100 groups.XST treatment groups were daily i.p.injected with 50 or 100 mg/kg XST for 60 days,respectively.The control and DM groups were given i.p.injection with saline.Blood glucose level and body weight were recorded every week.Histological changes in the retina tissues were observed with hematoxylin-eosin staining.Apoptosis and inflammation related factors,including cleaved caspase-3,glial fifibrillary acidic protein(GFAP),tumor necrosis factor-α(TNF-α)and intercellular cell adhesion molecule-1(ICAM-1)were detected by Western blot or real-time polymerase chain reaction.Then,the levels of advanced glycation end product(AGE)and its receptor(RAGE)were investigated.Tight junctions proteins(Zonula occludens-1(ZO-1),Occludin and Claudin-5)of blood-retinal barrier were detected by Western blot.The levels of retinal fifibrosis,transforming growth factor-β1(TGF-β1)-Smad2/3 signaling pathway were evaluated at last.Results There was no signifificant difference in the body weight and blood glucose level between XST and DM groups(P>0.05).Compared with the DM group,XST treatment signifificantly increased the retinal thickness of rats(P<0.05 or P<0.01),and suppressed cleaved caspase-3 expression(P<0.01).XST increased the protein expressions of ZO-1,Occludin and Claudin-5 and decreased the mRNA expressions of matrix metalloproteinase 2(MMP-2)and MMP-9(P<0.05 or P<0.01).Moreover,XST signifificantly reduced the productions of AGE and RAGE proteins in the retina of rats(P<0.05 or P<0.01),suppressed the over-expression of TNF-α,and decreased the elevated level of ICAM-1 in retina of rats(P<0.05 or P<0.01).XST signifificantly reduced the levels ofα-smooth muscle actin(α-SMA),connective tissue growth factor(CTGF),TGF-β1 and phosphorylation of Smad2/3 protein in rats(P<0.05 or P<0.01).Conclusions XST had protective effects on DR with possible mechanisms of inhibiting the inflammation and apoptosis,up-regulating the expression of tight junction proteins,suppressing the productions of AGE and RAGE proteins,and blocking the TGF-β/Smad2/3 signaling pathway.XST treatment might play a role for the future therapeutic strategy against DR.