Functional metabolomics reveal the role of AHR/GPR35 mediated kynurenic acid gradient sensing in chemotherapy-induced intestinal damage

Intestinal toxicity induced by chemotherapeutics has become an important reason for the interruption of therapy and withdrawal of approved agents. In this study, we demonstrated that chemotherapeutics-induced intestinal damage were commonly characterized by the sharp upregulation of tryptophan (Trp)-kynurenine (KYN)-kynurenic acid (KA) axis metabolism. Mechanistically, chemotherapy-induced intestinal damage triggered the formation of an interleukin-6 (IL-6)-indoleamine 2,3-dioxygenase 1 (IDO1)-aryl hydrocarbon receptor (AHR) positive feedback loop, which accelerated kynurenine pathway metabolism in gut. Besides, AHR and G protein-coupled receptor 35 (GPR35) negative feedback regulates intestinal damage and inflammation to maintain intestinal integrity and homeostasis through gradually sensing kynurenic acid level in gut and macrophage, respectively. Moreover, based on virtual screening and biological verification, vardenafil and linagliptin as GPR35 and AHR agonists respectively were discovered from 2388 approved drugs. Importantly, the results that vardenafil and linagliptin significantly alleviated chemotherapy-induced intestinal toxicity

Roudoukou-8 San reduces the hypoxia/reoxygenation injury of cardiac myocytes through JAK2/STAT3 pathway / 中国药科大学学报

@#To study the protective effects of Roudoukou-8 San extract on hypoxia/reoxygenation injury of cardiac myocytes and its relationship with tyrosine protein kinase 2(JAK2)/signal transducer and activator 3(STAT3)signaling pathway, hypoxia/reoxygenation injury model of H9c2 cells was built by sodium dithionite(Na2S2O4). The vitality of the cells was tested by CCK-8; the contents of lactate dehydrogenase(LDH), creatine phosphate kinase(CK)and aspartate aminotransferase(AST)in cell culture medium were tested by fully automatic biochemical analyzer; the contents of catalase(CAT), superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)in cells were tested by kits; cell apoptosis degree was tested by hoechst staining. And the protein expressions of JAK2, p-JAK2, STAT3, p-STAT3, Bcl-2 and Bax in myocardial cells of each group were tested by Western blot. Hypoxia for 1 hour and reoxygenation for 3 hours of 2 mmol/L Na2S2O4 caused damage of about 50% H9c2 cells. Compared with the model group, the extracts of Roudoukou-8 San with different concentrations could increase the viability of cells. Besides, contents of CK, LDH and AST in cell culture medium were decreased significantly, while contents of CAT, SOD and GSH-Px were increased significantly. At the same time, the expression of p-JAK2, p-STAT3 and Bcl-2 were significantly increased and that of Bax was significantly decreased. The effects of Roudoukou-8 San extract could bereduced by AG490 blocker. Therefore, Roudoukou-8 San extract possesses protective effects on Na2S2O4 induced-hypoxia/reoxygenation injury of cardiac myocytes through JAK2/STAT3 signaling pathway.

*AG490 could suppress bone marrow mesenchymal stem cells migration, mineralization and bone defect healing via inhibiting Jak2-STAT3 pathway / 中华口腔医学杂志

Objective@#To study the effect of Jak2-STAT3 pathway on cell proliferation, migration, mineralization and bone defect healing via simulating Jak2-STAT3 pathway inhibitor AG490 to bone marrow mesenchymal stem cells (BMSC) and bone defect mice models.@*Methods@#The effect of AG490 on BMSC proliferation was measured by MTT (methyl thiazolyl tetrazolium) assay. Regulation of AG490 on BMSC migration was tested by scratch assay and transwell assay. The BMSC migration related gene, matrix metalloproteinase (MMP)-7, MMP-9 and CXC subfamily receptor 4 (CXCR4), regulated by AG490 was studied by real-time PCR. Western blotting was adopted to analyze the regulation of Jak2-STAT3 phosphorylation through the simulation of AG490. The alizarin red staining and alkaline phosphatase (ALP) activity assay were performed to measure the effect of AG490 on BMSC mineralization and osteogenic differentiation. Mice femur bone defect models were built to analyzed the effect of AG490 on bone remodeling.@*Results@#AG490 significantly suppressed the migration rate of BMSC at 1 d and 2 d in the experiment group [(12.42±7.50) %, (41.8±2.6)%] compared with the control group [(55.5±9.9)%, (86.9±8.7)%] in scratch assay (P=0.000, P=0.000), the number of migrated BMSC in the experiment group (22.8± 5.9) was significantly suppressed compared with the control group (58.3±6.6) in Transwell assay (P=0.000). The expression of MMP-7, MMP-9 and CXCR4 were significantly downregulated in experiment group [(0.5± 0.1), (0.1±0.1) and (0.35±0.07)] compared with the control group [(1.1±0.1), (1.06±0.33), (1.08±0.13)] (P= 0.0003, P=0.000 and P=0.000). Also, the phosphorylation of Jak2-STAT3 was downregulated by AG490 in western blotting. After BMSCs were osteogenic induced for 14 days, the formation of mineralized nodule and the ALP activity of BMSC is significantly suppressed in experiment group (8.0±2.1) compared with the control group (35.7 ± 1.8) (P=0.0005). AG490 suppressed the bone defects healing,the expression level of phosphorylated Jak2 and phosphorylated STAT3, and the number of alkaline phosphatase positive cell at defect area in vivo is lower in experiment group than the control group. AG490 suppressed the relatively bone density at the defect area significantly (P=0.0004) at 5th week after the surgery.@*Conclusions@#AG490 could suppress proliferation, migration and mineralization to of BMSCs regulate bone defect healing via inhibiting Jak2-STAT3 pathway.

Effect of JAK-STAT signal transduction pathway blocker AG490 on the growth of xenograft tumor of hepatocellular carcinoma SMMC-7721 cells in nude mice / 肿瘤

Objective: To investigate the effect of AG490, an inhibitor of Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signal transduction pathway, on the growth and apoptosis of hepatocellular carcinoma SMMC-7721 cells in vivo, and to explore the possible mechanism. Methods: The xenograft tumor models of human hepatocellular carcinoma SMMC-7721 cells in nude mice were established. When the subcutaneous transplanted tumor grew to about 150 mm3, the mice were randomly divided into four groups, including saline treated control group, AG490 treated group, cisplatin (DDP) treated group, and AG490 combined with DDP treated group. Then the growth curves of xenograft tumors in different groups were drawn, the inhibitory rates of tumor growth were calculated, and the cell cycle and apoptosis were detected by FCM. The expression levels of phospho-STAT3 (p-STAT3) and caspase-3 in xenograft tumors were detected by immunohistochemistry and Western blotting. Results: Compared with the control group, the size of transplanted tumor was significantly decreased in DDP group, AG490 group and DDP combined with AG490 group after intraperitoneal injection with drugs for 10 and 13 days (all P<0.05). The inhibitory rate of tumor growth in AG490 combined with DDP group (60.24%) was significantly higher than that in DDP group (51.73%) or AG490 group (34.58%) (both P<0.05). The apoptotic rates of DDP group [(22.4±0.8)%], AG490 group [(40.1±1.2)%] and AG490 combined with DDP group [(43.2± 1.5)%] were significantly higher than that in the control group [(11.5±0.4)%] (all P<0.05). The positive rates of p-STAT3 expression in the control group, AG490 group, DDP group and AG490 combined with DDP group were (95.4±1.8)%, (65.8±2.4)%, (37.4±2.1)% and (20.3± 1.2)%, respectively; while the positive rates of caspase-3 expression in the above groups were (10.7±1.1)%, (26.4±1.6)%, (53.9±3.2)% and (82.5±2.8)%, respectively. The expression level of caspase-3 was significantly increased, while the expression level of p-STAT3 was decreased after treatment with AG490, DDP or their combination (all P<0.05). Conclusion: AG490 combined with DDP can further improve the synergistic inhibitory effect of DDP on tumor growth through blocking the expression of p-STAT3 protein and upregulating the expression of apoptosis-related protein caspase-3 in JAK2/STAT3 pathway.

Effects of a selective inhibitor of JAK2/STAT3 signaling pathway, AG490, on the biological behavior of human keloid-derived fibroblasts and their possible mechanisms / 中华皮肤科杂志

Objective To estimate effects of AG490, a selective inhibitor of JAK2/STAT3 signaling pathway, on the biological behavior of human keloid?derived fibroblasts (HKFs), and to explore their possible mechanisms. Methods In vitro cultured human skin fibroblasts(HSFs)and HKFs were both divided into several groups to be treated with AG490 at different concentrations (12.5, 25, 50, 75, 100 μmol/L), with those receiving no treatment serving as the control group. Then, cell counting kit?8(CCK?8)assay was performed to evaluate cellular proliferative activity of HSFs and HKFs after 24?, 48?and 72?hour treatment, flow cytometry to estimate cell cycle distribution and apoptosis rate in HKFs after 24?hour treatment, reverse transcription(RT)?PCR to measure STAT3 and cyclin D1 mRNA expressions in treated HKFs as well as STAT3 mRNA expression in untreated HSFs and HKFs after 24?hour culture, and Western blot analysis to measure the protein expressions of STAT3 and p?STAT3 in HSFs and HKFs after 24?hour treatment. Results CCK?8 assay showed that the proliferation inhibition rates of both HSFs and HKFs gradually increased along with the increase in AG490 concentrations and treatment duration, and the inhibitory effects increased in both dose?and time?dependent manners(all P<0.05). Besides, when cells were treated with the same concentrations of AG490 for same durations, the proliferation of HKFs were inhibited to a greater extent than that of HSFs(all P<0.05). As flow cytometry revealed, along with the increase of AG490 concentrations, the proportion of HKFs in G1 phase and the apoptosis rate in HKFs both increased gradually(all P < 0.01), while the proportion of HKFs in G2 phase gradually decreased(all P < 0.01), and the proportion of HKFs in S phase remained insignificantly changed. RT?PCR showed that the mRNA expression of STAT3 was significantly higher in untreated HKFs than in untreated HSFs after 24?hour normal culture(P < 0.05). After 24?hour treatment with AG490, the mRNA expressions of STAT3 and cyclin D1 in HKFs gradually decreased with the increase of AG490 concentrations. Correlation analysis revealed that the mRNA expression of cyclin D1 was positively correlated with that of STAT3 in AG490?treated HKFs (r = 0.855, P < 0.01). Western blot analysis showed that the protein expressions of both STAT3 and p ? STAT3 gradually decreased in HKFs and HSFs along with the increase of AG490 concentrations(all P < 0.05), and were significantly lower in HKFs than in HSFs (both P < 0.05). Conclusion AG490 can effectively inhibit HKF proliferation by selectively blocking the JAK2/STAT3 signaling pathway.

Activation Status and Biological Effects Analysis of STAT3 Signaling Pathway and Its Negative Regulator PIAS3 in Gliomas / 中国医科大学学报

Objective To discuss the activation and biological effects of STAT3 signaling pathway and its negative regulator PIAS3 in glioma cells. Methods Immunohistochemistry(IHC)was used to test the expression of p?STAT3 and PIAS3 in gliomas. AG490(60μmol/L),the in?hibitor of STAT3 signaling pathway,was used to treat U118 and U87 cells for 24/48 h,and the method of MTT assay was taken to evaluate the pro?liferation after AG490 treatment. The expression of p?STAT3 and PIAS3 was also examined by immunofluorescence(IF). Results There was no obvious significance between p?STAT3 and PIAS3 in nuclei or cytoplasm at different grades of gliomas. Whereas,p?STAT3 and PIAS3 were nega?tively correlated in the nuclei of vary grades malignancy gliomas. After AG490 treatment,U118 cells showed no obvious quantitative changes. How?ever,U87 cells showed obvious growth inhibition. IF results showed that there was no significant change at the levels of p?STAT3 and PIAS3 after AG490 treatment in U118 cells. However,the expression of p?STAT3 in the nuclei was down?regulated,and PIAS3 showed obvious nuclear translo?cation in U87 cells. Conclusion Nuclear translocation of PIAS3 plays the key role in modulating JAK/STAT signaling activation and inhibiting glioma cells proliferation.

Role of JAK/STAT signaling pathway in high glucose-induced damage in human umbilical vein endothelial cells / 中国病理生理杂志

AIM: To investigate whether Janus kinase/signal transducer and activator of transcription ( JAK/STAT) signaling pathway mediates high glucose-induced damage in human umbilical vein endothelial cells ( HUVECs ) . METHODS:The cell viability was examined by CCK-8 assay.The expression levels of JAK2, STAT3, caspase-9 and en-dothelial nitric oxide synthase ( eNOS) were detected by Western blot .The intracellular levels of reactive oxygen species ( ROS) were tested by DCFH-DA staining followed by photofluorography .Mitochondrial membrane potential ( MMP) was measured by rhodamine 123 staining followed by photofluorography .RESULTS:Treatment of HUVECs with high glucose (40 mmol/L glucose) for 6~12 h enhanced the protein level of phosphorylated JAK 2, peaking at 9 h.Treatment of the cells with high glucose for 6~12 h also increased the protein level of p-STAT3 with the peak value at 12 h.Pretreatment with the inhibitor of JAK/STAT pathway AG490 for 1 h before exposure of the HUVECs to high glucose significantly inhibi-ted the high glucose -induced injury , as evidenced by an increase in the cell viability , decreases in the expression of caspase-9 and the intracellular ROS production , and increases in MMP and the expression of eNOS .CONCLUSION:JAK/STAT signaling pathway is involved in the high glucose-induced damage in HUVECs .

The correlation between the soluble triggering receptor expressed on myeloid cells-1 and the janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway in rats with abdominal sepsis / 中华急诊医学杂志

Objective To investigate the correlation between the soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) and the janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway in rats with abdominal sepsis.Methods Using a sepsis model produced by cecal ligation and puncture (CLP),Wistar rats were randomly (random number) divided into normal control group (n =6),sham-operated group (n =24,) CLP group (n =48),AG490 (JAK2 inhibitor) treatment group (n =48) and rapamycin (RPM,STAT3 inhibitor) treatment group (n =48).At different intervals,the rats in each group were sacrificed,then the peripheral blood cells were harvested to detect the percent of CD4 + CD25 + Treg cells in CD4 + cells by flow cytometry.Meanwhile,mRNA of sTREM-1 from the tissue samples of the liver was also measured by real-time reverse transcription-polymerase chain reaction (RT-PCR).Results Compared with the normal control group and the sham-operated group,expression of sTREM-1 in the CLP group was significantly higher,and it showed a gradually increased tendency over time.At 6 and 24 hours,there were no significant differences in the expressions of sTREM-1 between the AG490 group (1.572 ± 0.051,2.063 ± 0.025,respectively) and the CLP group (1.592 ±0.036,2.082 ±0.021,respectively).But the expression of sTREM-lin the AG490 group (2.522 ± 0.083,3.153 ± 0.021,respectively) was lower than those in the CLP group (2.592 ±0.055,3.204 ±0.013,respectively) during 48 and 72 hours.In addition,there was no significant difference in the expression of sTREM-1 between the RPM group (1.581 ± 0.017) and the CLP group (1.592 ±0.036) at 6 hours.And the expression of sTREM-1in the RPM group (1.486 ±0.019,1.263 0.011,1.115 ± 0.022,respectively) was significantly lower than those in the CLP group (2.082 ± 0.021,2.592 ±0.055,3.204 ± 0.013,respectively) during 24 to 72 hours.Conclusions These data proved that blocking JAK/STAT pathway could inhibit the expression of sTREM-1 and decelarate the progress of inflammatory reaction in rats with abdominal sepsis.

Impact of AG490 on blood-brain barrier permeability and expression of interleukin-6 and tumor necrosis factor-αafter brain injury in rats / 中国脑血管病杂志

Objective To investigate the impact of AG490 on the blood-brain barrier (BBB ) permeability and the expression of interleukin-6 (IL-6 )and tumor necrosis factor-α(TNF-α)after traumatic brain injury (TBI)in rats. Methods A total of 144 healthy male SD rats were randomly divided into a control group,a trauma group,and an AG490 intervention group (n=48 in each group). The rats in each group were redivided into four subgroups (4 h,1 d,3 d,and 7 d subgroups)according to the time points after cerebral injury (n=12 in each subgroup). A brain trauma models were induced by hydraulic shock method. Evans blue was used to determine the changes of the BBB permeability after cerebral injury in each group. Real-time fluorescence quantitative PCR was to detect the expression levels of TNF-αand IL-6 mRNA in rat brain tissue. Immunohistochemistry was used to detect the expression of human phospho tyrosine kinase (P-JAK2). Results (1)The permeability of BBB:The permeability of BBB increased at 4 h,1 d,3 d and 7 d after brain injury in the trauma group (Evans blue permeation:10. 4 ± 1. 2,16. 0 ± 1. 4,22. 3 ± 2. 0,and 8. 4 ± 0. 9μg/g,respectively). Compared with the control group, there were significant differences (all P<0. 01). The Evans blue permeation of the AG490 intervention group were 9. 1 ± 1. 0,12. 8 ± 1. 1,17. 5 ± 1. 4 and 7. 1 ± 0. 8μg/g,respectively at each time point,and they were all significantly lower than those of the trauma group (all P<0. 01). (2)The expression of IL-6 and TNF-α mRNA:The expression levels of IL-6 mRNA and TNF-α mRNA at 4 h,1 d,3 d and 7 d after traumatic brain injury in the trauma group were 2. 31 ± 0. 35,2. 73 ± 0. 35,3. 32 ± 0. 29,2. 14 ± 0. 24 and 7. 46 ± 1. 18,9. 42 ± 1. 54,13. 76 ± 1. 89,and 6. 28 ± 1. 00,respectively,they were all significantly higher than those of the control group (all P<0. 01). The expression levels of IL-6 mRNA and TNF-α mRNA of the AG490 intervention group were 1. 14 ± 0. 22,1. 54 ± 0. 23,1. 94 ± 0. 32,1. 26 ± 0. 21 and 5. 57 ± 0. 88, 7. 78 ± 1. 02,11. 51 ± 1. 29,and 5. 05 ± 0. 97,respectively,they were all lower than those of the trauma group,but they still higher than the control group. There were significant differences (all P<0. 01). (3 )The expression of P-JAK2:The expression levels of P-JAK2-positive cells at each time point after traumatic brain injury in the trauma group were significantly higher than the control group (all P<0. 01),they were 17. 4 ± 2. 7,56. 2 ± 6. 7,26. 1 ± 5. 4,and 15. 3 ± 2. 5,respectively;those of the AG490 intervention group were 12. 2 ± 1. 4,41. 5 ± 4. 6,19. 4 ± 4. 1,and 9. 6 ± 2. 0,respectively,they were all lower than those of the trauma group,but still higher than the control group. There were significant differences (all P<0. 01). Conclusion During the acute phase after TBI,AG490 may activate the factor signaling pathways by inhibiting the non-receptor tyrosine kinase/signal transduction and transcription,significantly inhibit the expression of brain tissue inflammatory cytokines IL-6 IL-6 and TNF-α,reduce the BBB damage,and help to reduce secondary brain injury.

Modulatory effect of Evodiamine on JAK2/STAT3 signal pathway in HCT-116 cells / 中国药理学通报

Aim To investigate the inhibitory effect of Evodiamine on JAK2/STAT3 signal pathway in human colorectal cancer cell line HCT-116 . Methods Cells were cultured with 6. 0 μmol·L-1 Evodiamine for 2, 4 and 6 h, respectively. Cell nuclear morphology was detected by Hoechst staining and protein expression levels of JAK2 , p-JAK2 , STAT3 and p-STAT3 were examined by Western blot. Cells were treated with dif-ferent concentrations of AG490 for 48 h to select proper working concentration and cells treated with 6 μmol · L-1 EVO and 50 μmol · L-1 AG490 to compare the modulatory effect of EVO with AG490 on JAK2/STAT3 signal pathway. Results Hoechst staining revealed that Evodiamine could induce cells apoptosis, chroma-tin condensation gathered and typical apoptotic mor-phological changes in a time-dependent manner;West-ern Blot suggested that EVO could inhibit p-STAT3 significantly. After treatment with AG490, JAK2/STAT3 signal pathway was inactivated, the inhibitory effect of EVO on p-STAT3 was stronger than that of AG490 , while EVO combined with AG490 could fur-ther inhibit the expression of p-STAT3 significantly. Conclusions The anticancer effect of Evodiamine is mainly mediated by the modulation of JAK2/STAT3 signal pathway in HCT-116 cells.

HBx modulates apoptosis by activating JAK2/STAT3 signaling pathway in human renal proximal tubular epithelial cells / 中国病理生理杂志

AIM: To investigate the correlation of hepatitis B virus X protein (HBx) with renal tubular epithelialcell apoptosis in hepatitis B virus-associated glomerulonephritis (HBVGN) and the possible signaling mechanism. METHODS: The activation of JAK2/STAT3 signal pathway and the expression of apoptosis -related proteins in humankindey proximal tubular epithelial cells (HK-2 cells) were determined by Western blotting after transfection with HBx eukaryoticexpression vector.The cell proliferation was observed by CCK-8 assay.The cell apoptosis was analyzed by the imagingof HO33342 staining, transmission electron microscopy and flow cytometry with Annexin V /PI double staining.RESULTS:After transfection of the target gene HBx, the expression levels of both p-JAK2 and p-STAT3 were significantly increased.At the same time, the cell proliferation was obviously inhibited, and the apoptotic rate was increased.After incubationwith AG490, the JAK2/STAT3 signal pathway was partially blocked, and the cell apoptosis induced by HBx was reduced. CONCLUSION: HBx up-regulates the activation of JAK2/STAT3 signal pathway to induce renal tubular epithelialcell apoptosis, which is possibly involved in the pathogenic mechanism that HBV directly damages nephridial tissue .

Research progress on JAK/STAT signaling pathway and the inhibitor AG490 in lymphoma / 中国肿瘤临床

JAK/STAT includes many types of cell factors. Growth factor signal transduction is an important pathway and widely participates in cell multiplication, differentiation, and immunity adjustment. Aberrant-activated JAK/STAT signaling pathway is in-volved in carcinogenesis. Recent studies demonstrated that abnormal expression and activation of STAT3 were found in lymphoma. Constitutive activation of STAT3 promotes development, invasion, and metastasis of cancer. AG490, a JAK2 inhibitor, can block the JAK/STAT3 signal pathway and reduce the pathway's downstream STAT3 expression. Several studies showed that AG490 can inhibit cell proliferation and promote apoptosis in lymphoma. AG490 combined with chemotherapy drugs could improve sensitivity. In our study, we reviewed the potential role of JAK/STAT signaling pathway and the blocker AG490 in lymphoma.

lnhibition effect of AG490 on high glucose-induced epithelial-mesenchymal transition in human lens epithelial cells / 国际眼科杂志(Guoji Yanke Zazhi)

AlM:To study the relationship between JAK-STAT pathway and epithelial - mesenchymal transition in human lens epithelial cells. Meanwhile, the function of AG490 as a JAK inhibitor was also demonstrated in this article. METHODS:Human lens epithelial cells SRA01/04 ( LECs ) were treated by low concentration of glucose (5. 5mmol/L). High concentration of glucose (30. 5mmol/L) was used to treat the cells in order to form the high glucose model. According to adding AG490 or not, cells were divided into the control group and the experimental group, appropriate concentration 10ü mol/L and 50ü mol/L of AG490 were chosen and acting time of 6, 12, 24, 48h were selected. Effect of AG490 on cell migration was measured by wound healing test. The expression of TGF-β1 , FN,α-SMA mRNA were examined by RT-PCR. RESULTS:With the prolonged acting time ( 6, 12, 24 and 48h), cell activity increased in the HG group, as well as more expression of TGF-β1 , FN,α-SMA mRNA were detected compared to the LG group (P CONCLUSlON:JAK-STAT pathway takes part in high glucose-induced epithelial-mesenchymal transition in human lens epithelial cells. The mechanism is that it impacts the transcriptional expression of TGF- β1 and extracellular matrix. AG490, a JAK inhibitor, inhibits high glucose-induced epithelial-mesenchymal transition in human lens epithelial cells, And the inhibition enhances with the increasing concentration of AG490.

The effect of blocking the janus kinase signal transducers and activators of transcription signal pathway on the activity of Caspase-3 in the synovial tissue of rheumatoid arthritis rats / 中华风湿病学杂志

ObjectiveTo explore the effect of blocking the JAK/STAT signal pathway on the activity of Caspase-3 in the synovial tissue of rheumatoid arthritis rats.MethodsFifty rat models of collageninduced arthritis,which had arthritis index more than 2 were divided into the model group,the low dosage of AG490 group,the medium dosage of AG490 group and high dosage of AG490 group.Inaddition,6 rats were treated as normal control group.Normal saline,AG490 1,5,10 mg·kg-1 ·d-1 were given by intraperitoneal injection.Then the volume claws and pathologic scores of the rat models were recorded and the activity of Caspase-3 in the synovial tissue were compared.The results were analyzed by one-way ANOVA and LSD-t or Tamhane's T2 test.ResultsThe arthritis of the CIA models progressed fast,the volume of the claws and the pathological score of them were significantly higher than those of the control group.At the same time,no Caspase-3 positive express could be detected in the control group,whilethe model group had slightly increased expression.After different dosages of AG490 were applied,the swollen of joints was significantly improved compared with the model group.The histopathological score of the medium AG490 dosage of group and high dosage group(2.7±0.8,1.8+0.9) were remarkably decreased than those of the model group(4.3+1.2),the differences were statistically significant (P＜0.01).In addition,the Caspase-3 expression in the low,medium and high AG490 dosage group ( 1.90±0.15,3.13±0.33,3.56+0.34) was significantly higher than that of the model group(1.48±0.18)(P＜0.05 or P＜0.01 ).ConclusionBlocking JAK/STAT signal pathway can increase the activity of Caspase-3,reduce the excessive proliferation of synovial tissue,and improve arthritis symptoms.

The effect of the JAK/STAT signal pathway on apoptosis-related gene in the synovial tissue of rat rheumatoid arthritis / 中华风湿病学杂志

Objective To explore the effect of the JAK/STAT signal pathway on the apoptosis-related gene in the synovial tissue of rat rheumatoid arthritis (RA).Methods Fifty rat models of collagen-induced arthritis,whose arthritis index was more than 2,were divided into the model group,the low dose of AG490 group,the medium dose of AG490 group and the high dose of AG490 group.In addition,6 rats were treated intraperitoneal injection.Then,the arthritis index and the change of apoptosis-related genes were compared.Multiple-sample average was analyzed by single-factor x2 test and LSD-t or Tamhane's T 2 test were used for two-two comparison.Results The arthritis index of the model group increased evidently,and the apoptosis inhibitor Bcl-2,Bcl-xl gene and protein expression was up-regulated,which was significantly different when compared with that of the control group(0.931±0.035 vs 0.351±0.024,0.920±0.037 vs 0.271±0.029,0.322±0.047 vs 0.230±0.031 ).The expression of apoptosis promoting factor Bax wasslightly up-regulated.The blockage of JAK/STAT pathway cotld down-regulate the expression levels of the gene and protein of survivins Bcl-2 and Bcl-xl,and up-regulate the gene and protein expressions of Bax.Conclusion In the process of RA development,apoptosis inhibitor Bcl-2,Bcl-xl gene and protein expression is up-regulated.JAK/STAT signal transduction pathway regulates the apoptosis process.

Janus Kinase 2 Inhibitor AG490 Inhibits the STAT3 Signaling Pathway by Suppressing Protein Translation of gp130

The binding of interleukin-6 (IL-6) cytokine family ligands to the gp130 receptor complex activates the Janus kinase (JAK)/ signal transducer and activator of transcription 3 (STAT3) signal transduction pathway, where STAT3 plays an important role in cell survival and tumorigenesis. Constitutive activation of STAT3 has been frequently observed in many cancer tissues, and thus, blocking of the gp130 signaling pathway, at the JAK level, might be a useful therapeutic approach for the suppression of STAT3 activity, as anticancer therapy. AG490 is a tyrphostin tyrosine kinase inhibitor that has been extensively used for inhibiting JAK2 in vitro and in vivo. In this study, we demonstrate a novel mechanism associated with AG490 that inhibits the JAK/STAT3 pathway. AG490 induced downregulation of gp130, a common receptor for the IL-6 cytokine family compounds, but not JAK2 or STAT3, within three hours of exposure. The downregulation of gp130 was not caused by enhanced degradation of gp130 or by inhibition of mRNA transcription. It most likely occurred by translation inhibition of gp130 in association with phosphorylation of the eukaryotic initiation factor-2alpha. The inhibition of protein synthesis of gp130 by AG490 led to immediate loss of mature gp130 in cell membranes, due to its short half-life, thereby resulting in reduction in the STAT3 response to IL-6. Taken together, these results suggest that AG490 blocks the STAT3 activation pathway via a novel pathway.

Effect of Jak2 Inhibitor AG490 on Osteoclast Differentiation / 대한해부학회지

Osteoclasts are cells of hemopoietic origin that play an critical role in bone resorption and responsible for bone diseases, including osteoporosis, periodontal disease, and rheumatoid arthritis. In this study, we examined the effect of AG490, a Jak2-specific inhibitor on osteoclast differentiation. AG490 significantly inhibited receptor activator of NF-kappaB ligand (RANKL)-mediated osteoclast differentiation in a dose-dependent manner. RANKL stimulated the phosphorylation of p38, ERK, and JNK and promoted I-kappaB degradation. However, AG490 suppressed the phosphorylation of p38 induced by RANKL treatment. AG490 suppressed the mRNA expression of TRAP, c-Fos, NFATc1, and OSCAR in bone marrow-derived macrophages (BMMs) treated with RANKL. Also, AG490 significantly inhibited the protein expression of c-Fos and NFATc1 in response to RANKL. These results suggest that AG490 inhibited osteoclast differentiation by suppressing the expression of c-Fos and NFATc1.

Effect of matrine on signaling transduction pathway of JAK-STAT in SMMC-7721 cell line / 中草药

0.05). Conclusion Matrine could significantly down-regulate the mRNA expression of stat3 and stat5 and protein expression of STAT3 and STAT5 in SMMC-7721 cells. So matrine could inhibit the signaling transduction pathway of JAK-STAT and inhibit the proliferation of SMMC-7721 cells.

A study on prolonging survival time of rats following 90% hepatectomy / 中国普通外科杂志

Objective To observe the effects of atorvastatin and cytokine signaling inhibitor AG490 on the residual liver function and the survival time of 90% hepatectomy rats. Methods Rats were divided randomly into three groups after surgery: control group without treatment; Ato group administrated with atorvastatin (20 mg?kg -1?d -1) through NG tube one day before and three days after the surgery and AG490 group, intraperitoneally given AG490 (1 mg?kg -1?12h -1) beginning intraoperatively for 4 times. The health status and liver regeneration were observed and recorded. Results All rats in control group died within 24 hours. Both atorvastatin and AG490 significantly prolonged the survival time of rats after surgery (25.6 h & 30.6 h vs. 10.7 h,P

Effects of inflammatory mediator blocker on neurological deficits,apoptosis and expression of caspase-3 following cerebral ischemia-reperfusion in rats / 临床神经病学杂志

Objective To explore the effects of inflammatory mediator blocker AG490 on neurological deficits,apoptosis and expression of caspase-3 following cerebral ischemia-reperfusion(I/R) in rats.Methods The male SD rats were randomly divided into the groups sham-operation,I/R,saline and AG490;and the focal cerebral I/R models were made by middle cerebral artery thread embolism method.AG490(1 mg/kg) was intraperitoneal injection in AG490 group immediate and 12 h after ischemia-reperfusion respectively.The neurological deficits score was evaluated in 24 h after I/R in each group.The number of apoptosis in cerebral tissue was examined by d-utp nick end labeling staining(TUNEL).The expression of P-JAK2,P-STAT3,caspase-3 were detected by Western Blot.Results Compared with the groups I/R and saline,the neurological deficits score in AG490 group was significantly decreased(all P