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ObjectiveTo explore the underlying mechanism of Tripterygium wilfordii polyglycoside tablets （TWPT） in the prevention and treatment of kidney injury in diabetic nephropathy （DN） through the nuclear factor of activated T-cells 2（NFAT2）/cyclooxygenase-2（COX-2） pathway. MethodForty-two male SD rats of SPF grade were selected and randomly divided into a normal group （n=8） and an experimental group （n=34） after one week of adaptive feeding. The rats in the normal group were fed conventionally. The DN model was established in rats of the experimental group by intraperitoneal injection of streptozotocin （STZ） following one week of feeding on a high-fat and high-glucose diet. After the death and failure cases during modeling were eliminated， the remaining 24 model rats were randomly divided into model group， valsartan （8.33 mg·kg-1·d-1） group， and TWPT （5 mg·kg-1·d-1） group. Rats in normal group and model group were given equal amounts of normal saline by gavage. After six weeks， body weight was measured and urine samples were collected. Blood samples were collected from the abdominal aorta， and then the rats were sacrificed for sampling. Biochemical indicators， such as serum blood urea nitrogen （BUN）， serum creatinine （SCr）， alanine aminotransferase （ALT）， blood lipid， blood glucose， and 24-hour urine total protein （24 h UTP）， were determined. Hematoxylin-eosin （HE） staining and Masson staining were used to observe the pathology of the kidney. Enzyme-linked immunosorbent assay （ELISA） was used to detect NFAT2 and COX-2 expression levels in the serum. Western blot and Real-time fluorescence quantitative polymerase chain reaction（Real-time PCR）were adopted to detect NFAT2， COX-2 protein and mRNA expression in kidney tissues， respectively. ResultCompared with the normal group， the model group showed elevated 24 h UTP， BUN， SCr， CHO， TG， and FBG， increased serum NFAT2 and COX-2 production and expression （P<0.01）， and elevated protein and mRNA expression of NFAT2 and COX-2 in kidney tissues （P<0.01）. In addition， the pathology of the kidney showed enlarged glomeruli， mild proliferation of mesangial cells， and widened mesangial stroma. Compared with the model group， the TWPT group showed decreased 24 h UTP， BUN， SCr， CHO， TG， and FBG （P<0.05，P<0.01）， basically normal glomerular morphology， decreased expression of serum NFAT2 and COX-2 （P<0.01）， and down-regulated protein and mRNA expression of NFAT2 and COX-2 in kidney tissues （P<0.01）. ConclusionTWPT can alleviate 24 h UTP in DN model rats， protect renal function， and improve renal pathology， and its mechanism of action may be related to the down-regulation of NFAT2/COX-2 expression in the serum and kidney tissues.
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ObjectiveTo explore the effect of Xiao Xianxiongtang （XXXT） on the transforming growth factor （TGF）-β1-induced invasion， metastasis， and epithelial-mesenchymal transition （EMT） of gastric cancer MGC-803 cells and the underlying mechanism. MethodThe molecular docking between XXXT and nuclear factor of activated T cells （NFAT） was performed by CB-DOCK （http：//clab.labshare.cn/cb-dock/）. The invasion and metastasis model of MGC-803 cells was established with 10 μg·L-1 TGF-β1. MGC-803 cells were classified into blank group， model group， 0.1 g·L-1 XXXT group， 0.2 g·L-1 XXXT group， and 0.4 g·L-1 XXXT group. For further clarifying the key role of Wnt5a/Ca2+/NFAT signaling pathway in the inhibition of XXXT on gastric cancer， MGC-803 cells were transfected with Wnt5a overexpression plasmid， and then the cells were classified into blank plasmid group， Wnt5a-OE group， blank plasmid + XXXT （0.4 g·L-1） group， and Wnt5a-OE + XXXT （0.4 g·L-1） group. Cell viability was determined by cell counting kit-8 （CCK-8） assay， cell invasion and migration ability by Transwell invasion assay and wound healing assay， expression of EMT-related proteins （E-cadherin， N-cadherin， Vimentin， Snail） and Wnt5a/Ca2+/NFAT signaling pathway-related key proteins ［Wnt5a， calcineurin （CaN）， NFAT1， and p-NFAT1］ by Western blot， and changes in intracellular Ca2+ concentration by immunofluorescence assay. ResultMolecular docking suggested that XXXT acted on Wnt5a/Ca2+/NFAT signaling pathway. XXXT （0.1， 0.2， 0.4 g·L-1） significantly promoted the loss of MGC-803 cell viability （P<0.05，P<0.01）. It inhibited cells from invading the transwell lower chamber and slowed down the healing of cell wounds in a dose-dependent manner （P<0.05， P<0.01）. Moreover， it promoted the expression of E-cadherin while suppressed the expression of N-cadherin， Vimentin， and Snail （P<0.05， P<0.01）. Further experiments showed that XXXT could inhibit the expression of Wnt5a， CaN， NFAT1， and p-NFAT1， and reduce the nuclear expression of NFAT1 and the transcription activity mediated by NFAT1， so as to reduce the cellular Ca2+ concentration （P<0.05， P<0.01）. XXXT can reverse the effect of Wnt5a （P<0.05， P<0.01）. ConclusionXXXT can attenuate the invasion， metastasis， and EMT of MGC-803 cells via the Wnt5a/Ca2+/NFAT pathway， thereby weakening the tumor-promoting effect of TGF-β1. In summary， XXXT may exert therapeutic effect on gastric cancer by regulating the invasion， metastasis， and EMT of gastric cancer cells.
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BACKGROUND: Preliminary study found that polylactic acid composite material could accelerate the bone construction rate, and the underlying mechanism still needs to be studied further. OBJECTIVE: To investigate the effect of lactic acid at different concentrations on osteoclast differentiation of mononuclear cells in mice. METHODS: Mouse RAW264.7 cells were cultured in DMEM with 0 (control group), 5, 10 and 20 mmol/L lactic acid, respectively, under the induction of 50 µg/L RANKL for 5 days. The effect of lactic acid concentration on the cell proliferation rate was analyzed by cell counting kit-8 assay. Tartrate resistant acid phosphatase positive polykaryotic cells were stained and counted with tartrate resistant acid phosphatase staining kit. mRNA expression levels of acid phosphatase 5, nuclear factor of activated T-cells 1 and RANK were detected by RT-PCR. Protein expression levels of cathepsin K and nuclear factor of activated T-cells 1 were detected by western blot assay. RESULTS AND CONCLUSION: (1) 5 mmol/L lactic acid produced the highest proliferation rate of raw264.7 cells, whereas the 20 mmol/L lactic acid produced lowest cell proliferation rate. Compared with the control group, the proliferation rate of raw264.7 cells by 10 mmol/L lactic acid was insignificant. (2) Tartrate resistant acid phosphatase staining showed the highest positive rate and mRNA expression levels of acid phosphatase 5, nuclear factor of activated T-cells 1 and RANK under the condition of 10 mmol/L lactic acid. (3) With the increase of lactic acid concentration, the expression level of cathepsin K increased, while the expression level of nuclear factor of activated T-cells 1 was on a decline. (4) Under the current experimental conditions, with the increase of lactic acid concentration, the ability of lactic acid to promote the osteoclast differentiation of mouse RAW264.7 cells is firstly increased and then decreased, and 10 mmol/L lactic acid was the optimal concentration to promote the osteoclast differentiation of mouse RAW264.7 cells. Lactic acid can affect the osteoclastic differentiation of mouse raw264.7 cells by nuclear factor of activated T-cells 1 in nuclear factor-KB signaling pathway.
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Objective The aim of this study was to investigate the effect of Ca2+ /calmodulin - dependent kinase II (CaMKII)γ RNA interference on the expression of nuclear factor of activated T-cells cytoplasmic 1(NFATc1),tyrosine kinase(c-Src)and tartrate resistant acid phosphatase(TRAP)genes,and its role and molecular mechanism in osteoclast differentiation. Methods The CaMKII γ RNA interference vector was constructed by lentivirus and transfected into RAW264. 7 cells. The experiment was di-vided into three groups:A,B and C,which were the control group,negative vector group and interference vector group. After transfec-tion for 12 hours,osteoclasts induced by 50 ng/mL RANKL and the cells were harvested after induction for 5 days. Real-time quanti-tative PCR,Western blot and immunofluorescence were used to detect the expression of NFATc1,TRAP and c-Src genes in three groups. Results The mRNA levels of NFATc1,TRAP and c-Src in the group C decreased by 49. 86% ,43. 65% and 53. 57% ,re-spectively(P<0. 001),and the protein levels decreased by 54. 22% ,46. 75% and 45. 86% ,respectively(P<0. 001). There was no significant difference between the A and the B groups(P>0. 05). The fluorescence intensity of the above genes in the group C was significantly weaker than that in the A and B groups,and the formation of osteoclasts was significantly less than that in the A and B groups. Conclusion CaMKIIγ RNA interference significantly inhibited the expression of NFATc1,TRAP and c-Src genes,sugges-ting that CaMKIIγ plays a key regulatory role in osteoclast differentiation.
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The NFAT protein signaling pathway plays an important role in the regulation of cell function,such as cell proliferation,differentiation,invasion,metastasis,angiogenesis and tumor microenvironment,and it is also important in the development in embryogenesis,organogenesis,immune response and inflammatory response.Although the NFAT family has been shown to be a key role in the development of tumors,the different isoforms of the NFAT family play a different role in different cells,to understand the role and mechanism of the NFAT family in tumor development and progression will help to develop new strategies for targeting NFAT tumor therapy.
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Objective To investigate the function of cAMP response element binding protein (CREB) and extracellular signal-regulated kinase (ERK1/2) in osteoclast differentiation mediated by Ca2+/calmodulin-dependent kinase Ⅱ (CaMK Ⅱ)δ,and elucidate the molecular mechanism thereof.Methods CaMK Ⅱδ RNA interference lentivirus vector was constructed and mouse RAW264.7 cells were transfected with the virus to determine the interference efficiency.After virus transfection,RAW264.7 cells were treated with 50ng/ml receptor activator of nuclear factor κB ligand (RANKL) and the phosphorylation levels of CREB and ERK1/2 were detected at different time points.The cells were also treated with PD98059,an ERK1/2 inhibitor,to determine the effect of ERK1/2 signal blocking on the expression of nuclear factor activated T-cells cytoplasmic 1 (NFATc1) and osteoclast differentiation.Results Interference efficiency of recombinant CaMK Ⅱδ virus vector was 77.2％ at mRNA level and 70.2％ at protein level.CaMK Ⅱδ RNA interference significantly suppressed phosphorylation of CREB and ERK1/2,and the levels ofp-CREB and p-ERK1/2 were down-regulated by 21％-55％ and 55％-64％,respectively.ERK1/2 inhibitor significantly down-regulated the protein expression of NFATc1,and the number of osteoclast,the number and size of bone resorption lacunae decreased by 39.3％,50.0％ and 52.3％,respectively.Conclusion CaMK Ⅱδ RNA interference may significantly suppress the phosphorylation of CREB and ERK1/2,and CREB and ERK1/2 have mediated the CaMK Ⅱδ-induced osteoclast differentiation.
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OBJECTIVE To evaluate whether the IDO1 inhibitor 1- methyl- L- tryptophan (1- MT) combine calcium influx inhibitor carboxyamidotriazole (CAI) could further enhance the suppression of programmed death 1 (PD-1) in CD8 + T cells and investigate the curative effect of the combined use. METHODS CD8 +T cells were isolated from normal mice spleen by negative selection using magnetic cell separation. The isolated CD8 +T cells were cultured in RPMI 1640 medium containing 10% FBS and 100 U·mL- 1 IL-2 and activated by the addition of anti-CD3 and anti-CD28 (1 g·L- 1 each mabs). CD8 + T cells were pretreated for 48 h with drug and the fluo- 3 as a marker of intracellular calcium concentration was detected by flow cytometry. The calcineurin (CaN) levels were assayed with ELISA in CD8+T cells after 48 h incubation with 10 μm CAI. The nuclear translocations of NFAT and AHR were detected by immunofluorescent staining after 48 h of drug treatment. The expression of PD-1 in CD8+T cells was analyzed by flow cytometry. RESULTS Intracellular fluorescent intensity was markedly debase due to CAI treatment(P<0.01). Meanwhile, the changes of CaN content had a resembled correlation (P<0.01). Immunofluorescence experiment showed that after combination therapy the transfer of NFAT and AHR in nuclear substantially reduced. Flow cytometry revealed that after the combination caused a significant decrease in PD-1 expression in CD8+T cells. CONCLUSION CAI and 1-MT could inhibit markedly the expression of PD-1 in CD8 +T cells by inhibiting the nuclear translocation of NFAT and AHR, respectively and the combination of them has synergetic effect.
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Objective To construct a Luciferace reporter vector containing the 3'untranslated region (3'UTR) of NFAT5 and measure the correlation between NFAT5 and miR-155.Methods The miR-155 targeting NFAT5 3'UTR was predicted by Target Scan,Mir Base and Pic Tar.NFAT5 and mutant NFAT5 sequence(NFAT5-mu) were then designed and synthesized,and they were cloned into pMIR-REPORTTM Luciferace reporter vector.Human embryonic kidney-293AD (HEK-293AD) cells of the 4th passage were divided into 4 groups according to the random number table.cells in plasimd +miR-155 mimics groups were transfected with pMIR-NFAT5 recombinant plasimid,pRL-Tk plasmid and miR-155 mimics;cells in plasimd + miR-155 mutated groups were transfected with pMIR-NFAT5-mu recombinant plasimid,pRL-Tk plasmid and miR-155 mimics;cells in plasimd + miR-155 control groups were transfected with pMIR-NFAT5 recombinant plasimid,pRL-Tk plasmid and miR-155 Negative control;cells in plasimd +miR-155 inhibitor were transfected with pMIR-NFAT5 recombinant plasimid,pRL-Tk plasmid and miR-155 inhibitor;and were respectively transfected into together by liposome.After culture for 24 h,the luciferase activity was detected by dual luciferase reporter assay system.Results TargetScan,Miranda and PicTar shared the results that NFAT5 has the complementary binding sites with 3'UTR of miR-155.And luciferase reporter vectorwas constructed.Therefore the result of sequencing and double digesting of recombined plasmid were completely correct.Dual-luciferase reporter assay showed that miR-155 possesses a target effect on 3'UTR of NFAT5.Compared to the pMIR-NFAT5 + miR-control group,the luciferase activity of the pMIR-NFAT5 + miR-1 5 5 mimics group was decreased,with statistically significant difference(P＜0.01),while there was no significant difference at other time points(P＞0.05).Conclusion The pMIR-NFAT5 recombinant plasmid and pMIR-NFAT5 recombinant mutated plasmid were confirmed with successful construction.and it was found that miR-155 can target NFAT5 mRNA 3'-UTR.The results provide the experiment data for further disclosing the mechanism of inhalation injury on the level of gene expression.
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Objective To illustrate that tumor necrosis factor-α (TNF-αt) / nuclear factor of activated T cells pathway is the main function way that mesenchymal stem cells (MSC) inhibit proliferation of pulmonary vascular smooth muscle cells during treating pulmonary hypertension (PH).Methods MSC from human umbilical cord was used to treat PH rat models induced by monocrotaline.Rats were divided into the control group,the PH model group and the MSC group.The general conditions of the rats were observed.Haemodynamics was detected.Pathological sections and immunohistochemistry method were used to detect the lung structure and tissue changes.Changing conditions of TNF-αt/NFAT were detected.Results Compared with rats in the PH model group,the general conditions of the MSC group tended to be normal evidently:the right ventricular systolic pressure (RVSP) dropped [(30.37 ±3.13) mmHg vs.(47.90 ± 3.45) mmHg,1 mmHg =0.133 kPa],the aortic pressure (MAoP) increased [(115.03 ± 16.01) mmHg vs.(92.78 ± 16.28 mmHg)],the thickening condition of arterial intima-media was evidently relieved [(17.22 ±1.21)％ vs.(31.68 ±2.26)％],the plasma TNF-α level decreased obviously [(842 ±76) ng/L vs.(245 ±24)ng/L],and the lung tissue TNF-o level decreased (0.172 ±0.024 vs.0.248 ± 0.051),and all the differences were statistically significant (all P ＜ 0.05).The activation of pulmonary artery NFATc2 in the MSC treatment group was apparently inhibited.Conclusions MSC therapy may perform the treating effect in PH by inhibiting the over-proliferation of inflammation related pulmonary vascular smooth muscle cells via TNF-oα/NFAT pathway.
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Objective To study the effect of zoledronate (ZOL) on Ca2+/calmodulin-dependent kinase Ⅱ δ (CaMK Ⅱ δ) and down-stream gene expressions during osteoclast differentiation.Methods Mouse osteoclast precursors RAW264.7 cells were divided into the control group and ZOL group.The cells in both groups were induced with 50μg/L receptor activator of nuclear factor kappa B ligand (RANKL) and were harvested on 5 d,while the cells in ZOL group were also simultaneously treated with 1 × 10-6 mol/L ZOL for 2 d.Five days later,the cells were harvested and examined osteoclastogenesis,as well as gene expressions of CaMK Ⅱ δ,nuclear factor of activated T-cells cytoplasmic 1 (NFATc1),tartrate-resistant acid phosphatase (TRAP) and cell-sarcoma receptor coactivator (c-Src).Results The number of TRAP positive multinuclear osteoclasts,number and size of dentin absorption lacunae and area in the ZOL group were (20.0±3.2),(18.0±4.2) and (6 335.3± 1 043.2)μm2 respectively,which were significantly lower than (36.0 ± 8.4),(37.2 ± 5.0) and (11 636.2 ± 3 661.1) μm2 in the control group and decreased by 44.4 ％,51.6 ％ and 45.6 ％ respectively (P＜0.01).ZOL also significantly inhibited the gene expressions of CaMK Ⅱ δ,NFATc1,TRAP and c-Src,and the mRNA levels of these genes were decreased by 44.1％,49.0％,53.8％ and 49.6％ respectively,the protein level were decreased by 43.5 ％,32.2 ％,45.5 ％ and 48.0 ％ respectively.The immunofluorescent cytochemistry detection results showed the fluorescence intensity of CaMK Ⅱ δ,NFATc1,TRAP and c-Srcin in the ZOL group was significantly weakened when compared with the control group.Conclusion ZOL could significantly inhibit the osteoclast formation and bone absorption function,and down-regulates gene expressions of CaMK Ⅱ δ,NFATc1,TRAP and c-Src in osteoclast differentiation.
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AIM: To investigate the role of G-protein-coupled bile acid receptor 1 ( GPBR1; also known as TGR5) activation in high glucose-induced cardiomyocyte hypertrophy and calcineurin (CaN)/nuclear factor of activated T-cells 3 (NFAT3) signaling.METHODS:Primarily cultured mouse cardiomyocytes were used in the study .The cell surface areas of the cardiomyocytes were measured by an image analysis system .The cell protein content was detected by BCA meth-od.The expression of TGR5, CaN and NFAT3 at mRNA and protein levels was determined by RT-PCR and Western blot . RESULTS:The mouse cardiomyocytes were successfully cultured .High glucose significantly induced the increases in the cell surface area, the cell protein content and the expression of CaN and NFAT 3 (P<0.05) in the cardiomyocytes.TGR5 activation or a CaN antagonist cyclosporin A inhibited high glucose-induced cardiomyocyte hypertrophy and the expression of CaN and NFAT3 (P<0.05).These effects of TGR5 activation were abolished by TGR5 gene interference (P<0.05). CONCLUSION:TGR5 activation reduces high glucose-induced cardiomyocyte hypertrophy by inhibiting CaN /NFAT3 sig-naling.
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Calcineurin (CaN) serves as a key enzyme in human immune regulation. The most important target of this enzyme is the transcription factors of nuclear factors of activated T cells (NFATc). The discovery of the immunosuppressive function of CaN inhibitors (CNIs),ciclosporin A (CsA) and tacrolimus (FK506),has helped overcome the immune rejection of organ transplantion and changed organ transplantion fundamentally. Both of these drugs are still widely used in clinical and basic research,but their therapeutic effects are limited by their serious side effects,including renal tox?icity and neurotoxicity. Therefore,the development of new CNIs with higher specificity and fewer side effects in the clinic is a focus of research. In this paper,the newly discovered and synthesized CNIs in recent decades,including the CsA and FK506 derivatives,direct inhibitors of CaN,as well as the inhibitors that specifically interfere with CaN-NFATc interaction,were summarized.
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AIM:To study the morphological changes of cardiac H9c2 cells during the developmental process of fetal rat.METHODS:Embryonic rat heart-derived H9c2 cells were maintained in DMEM supplemented with 10%fetal bovine serum.The H9c2 cells were plated at a density of 6 000 cells/cm and divided into 5 groups:H9c2 cells were trea-ted with 5 mmol/L glucose, 25 mmol/L glucose, 50 mmol/L glucose, Norvasc (25 nmol/L) +25 mmol/L glucose, or Norvasc (25 nmol/L)+50 mmol/L glucose for 48 h.The morphology of H9c2 cells was observed.The cell surface area was measured by Image-Pro Plus 6.1 software.Fluorescence spectrophotometry was used to detect the concentration of in-tracellular calcium ion ( [ Ca2+] i ) in the cardiomyocytes.The concentration of CaN in the cell was measured by ELISA. The mRNA expression of CaNAβ, NFAT3 and β-MHC in the cells was detected by real-time PCR.The protein levels of CaNAβ, NFAT3 and β-MHC in cultural H9c2 cells were detected by Western blot.RESULTS: The mean area of the cells, the mean fluorescence value of [ Ca2+] i and the concentration of CaN in 25 mmol/L glucose group were higher than those in 5 mmol/L glucose group, and those were lower than those in 50 mmol/L glucose group.After treated with Nor-vasc, those results decreased significantly.The expression of CaNAβ, NFAT3 andβ-MHC at mRNA and protein levels in 25 mmol/L glucose group was higher than those in 5 mmol/L glucose group, but was lower than those in 50 mmol/L glu-cose group .The expression of CaNAβ, NFAT3 andβ-MHC at mRNA and protein levels decreased significantly in Norvasc treatment group.CONCLUSION:Ca2+-CaN-NFAT3 signaling pathway is perhaps involved in high glucose-induced H9c2 cardiomyocyte hypertrophy.
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Objective: To observe the regulatory effect of nuclear factor of activated T-cells (NFAT)-1, 4, 5 on ADAMTS-4. promoter activity in nucleus pulposus cells, so as to discuss the underlying molecular mechanism of intervertebral disc degeneration. Methods: The ADAMTS-4-pβ-gal-Basic was inserted into PGL3-Basic vector after double digestion by the restriction enzyme Xho I and Hind III. The purified PGL3-ADAMTS-4 plasmid was obtained through screening. Rat nucleus pulposus cells were cultured in vitro and, via Lipofectamine2000 transfection reagent, transfected with NFAT-1, NFAT-4, NFAT-5 or DN-TonEBP expressing plasmids with or without appropriate backbone vector and 175 ng ADAMTS-4 promoter. The normal cells were taken as controls and transfected cells were taken as treatment group. Dual-Luciferase™ reporter assay system was used to detect the effect of NFAT-1, 4, 5(TonEBP) on ADAMTS-4 promoter activity. Results: We successfully constructed PGL3-ADAMTS-4 plasmid and identified two NFAT-Bind elements in the promoter. Compared with the control group, ADAMTS-4 promoter activity was significantly inhibited in NFAT-1 group (P 0. 05). Conclusion: NFAT-1 can regulate ADAMTS-4 expression, which may play a role in modulating aggrecan content in the intervertebral disc physiology and/or intervertebral disc degeneration, providing a new strategy for biological treatment of intervertebral disc degeneration.
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Background and purpose:It was reported that nuclear factor of activated T cells (NFAT) is closely related with carcinomas. Esophageal squamous cell carcinoma (ESCC) is one of the most common carcinomas in China. The present study investigated the expression and clinical significance of NFAT isoforms in ESCC. Methods:The expression of NFAT isoforms and the differences in different pathological levels of ESCC were detected in 104 specimens of human ESCC tissues and normal esophageal tissues by immunohistochemistry. Results:This study found that the positive rates of NFAT1 (53.8%), NFAT2 (10.6%), NFAT3 (26.9%), NFAT4 (45.2%) expression were significantly higher in tumor tissues than in adjacent normal esophageal tissues (P<0.001), respectively. The positive rate of NFAT1 expression was significant-ly higher in drinkers (62.3%) than nondrinkers (37.1%, P=0.01), and also higher in patients with lymph node metastasis (68.4% vs 5.5%, P=0.002) and with late stage (58.7% vs 36.2%, P=0.02). Multivariate analysis showed that NFAT1 expression was correlated with lymph node metastasis. The positive rate of NFAT3 was significantly higher in patients with lymph node metastasis (39.4%) than in those without lymph node metastasis (19.7%, P=0.03). Conclusion:These results suggest that the overexpression of NFAT1 and NFAT3 is associated with lymph node metastasis in ESCC.
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Objective To study the immunosuppressive mechanism of alkaloid sinomenine (SIN) by observing the effects of SIN on the proliferation and intracellular protein expression levels of nuclear factor of activated T cells (NF-AT) and interferon-gamma (IFN-γ) in CD4+ T lymphocytes of human periphery blood. Methods CD4+ T lymphocytes were isolated from PBMC suspensions with immunomagnetic beads and divided into five groups to culture. (1) Negative control group: no medicine was added to cell culture medium; (2) Positive control group: CsA solution (final concentration: 50ng/ml) was added to cell culture media; (3) Low-concentration SIN group (L-SIN): low-concentration SIN solution (final concentration: 10 μmol/L) was added to cell culture media; (4) Middle-concentration SIN group (M-SIN): middle-concentration SIN solution (final concentration: 200 μmol/L) was added to cell culture media; (5) High-concentration SIN group (H-SIN): high-concentration SIN solution (final concentration: 1000 tmol/L) was added to cell culture media. The proliferations of CD4+ T lymphocytes were observed. Western blotting was performed to detect the protein expression levels of NF-AT. FCM was used to determine the levels of IFN-γ. Results Compared with negative control group, the cell proliferation was significantly inhibited in H- and M-SIN groups (P＜0. 01 ). SIN concentration-dependently inhibited the protein expression levels of NF-AT and IFN-γ in CD4+ T lymphocytes of human periphery blood (P＜0.01). The protein expression levels of NF-AT and IFN-γ were lowest in positive control group. There was a close negative correlation between intracellular levels of NF-AT and cell proliferation inhibition ratio in CD4+ T lymphocytes of human periphery blood (rs = - 0. 969, P = 0. 000). Conclusion SIN can inhibit the protein expression of NF-AT and IFN-γ in CD4+ T lymphocytes of human periphery blood probably by decreasing protein levels of NF-AT to inhibit the activity and proliferation of CD4+ T lymphocytes.
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Mechanism studies in the gene regulation in the eukaryotic cells is one of the momentous areas in molecular biology.Regulation at transcription level is a complex progress with multiple steps with the presence of the gene functions.There exist ubiquitous occurrence of transcription factors in mammalian tissues and biodiversity in the factors.These transcription factors are found to relate closely to various carcinogeneses,including cell proliferation,apoptosis,invasion and angiogenesis.Understanding of transcription factors and their action mechanisms,through the activation and inhibition of transcription factors,would potentially lead to the discovery of new entities in the targeting treatment and prevention of the cancer diseases.
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AIM: To investigate the role and signal mechanism of PPAR-α in the pathogenesis of cardiac hypertrophy. METHODS: Small interfering RNA (siRNA) was applied to efficiently silence the gene expression of PPAR-α in cardiac myocytes. [~3H] leucine incorporation assay was performed to measure protein synthesis. Reverse transcription-polymerase chain reaction (RT-PCR) was used to analyze the mRNA level of atrial natriuretic factor (ANF) and PPAR-α. Western blotting analysis was performed to investigate the levels of phosphorylation of protein kinase B (PKB/Akt) and glycogen synthase kinase 3β (GSK3β). Immunofluorescence analysis was used to examine the cellular localization of NFATc4. RESULTS: (1)RSS304168 was the most efficient stealth RNAi duplex to specifically inhibit PPAR-α expression. (2)RSS304168 significantly potentiated the ET-1-induced cardiomyocyte hypertrophy and enhanced ET-1-induced protein synthesis and ANF mRNA expression in cardiomyocytes. Moreover, RSS304168 completely reversed the inhibitory effects of fenofibrate on ET-1-induced protein synthesis and ANF mRNA expression. (3)RSS304168 enhanced ET-1-induced phosphorylation of Akt at Ser473 and GSK3β at Ser9. The effects of ET-1 or ET-1 combined with RSS304168 on phosphorylation of Akt/GSK3β were completely blocked by LY294002, a PI3K specific inhibitor. Fenofibrate markedly inhibited ET-1-induced phosphorylation of Akt/GSK3β while RSS304168 abolished these effects of fenofibrate. (4)Fenofibrate prevented the nuclear translocation of NFATc4 induced by ET-1 while RSS304168 abolished this effect of fenofibrate. CONCLUSION: Activation of PPAR-α inhibits ET-1-induced cardiomyocyte hypertrophy through blocking Akt/GSK3β-NFATc4 signaling pathways.
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Objective Calcineurin-NFAT pathway in the regulation of VSMCs proliferation induced by catecholamines.Methods Primary VSMCs from rat aorta were used as the experimental model.Proliferation of VSMCs was measured by MTT assay and cell count.Calcineurin protein and its activity were assayed with immunoblotting and free inorganic phosphate content analysis respectively.Localization of NFATc1 was detected by immunofluorescence staining.Results Phenylephrine(PE,an ?1-adrenoceptor agonist) increased VSMCs proliferation.Prazosin(an ?1-adrenoceptor antagonist),cyclosporin A(CsA,an inhibitor of calcineurin) and chelerythrine(an inhibitor of PKC) decreased PE-induced absorbance and cell number.Timolol(?-adrenoceptor antagonist) has no effect on absorbance and cell number induced by PE.Additional treatment with CsA further inhibited PE-induced absorbance and cell number compared with the chelerythrine pretreatment group.CsA and chelerythrine alone had no significant effect on either absorbance or cell number.CsA decresed PE-induced alcineurin level and its activity.NFATc1 was translocated from cytoplasm to nucleus upon treatment with PE.This translocation was reversed by CsA.Conclusion CsA partially inhibits PE-induced VSMCs proliferation via inhibiting calcineurin activity and NFATc1 nuclear translocation.Calcineurin-NFATc1 pathway is involved in hyperplastic growth of VSMCs induced by catecholamines.
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Aim To study the involvements of nuclear factor of activated T-cells (NFATc) and NFκB in calcineurin-mediated ischemic brain damage in vivo. Methods The rat transient forebrain ischemia conducted through 15 min ischemia followed by 8, 24, and 72 h reperfusion was induced using the fourvessel method. The rats were divided randomly into five groups; sham control group, ischemia/reperfusion (I/R) group, CsA treated groups (for 8, 24, and 72 h reperfusion). Western blotting was performed to detect changes of FasL, NFATc, I-κB-α, and phospho-I-κB-α protein expression, and gel shift assays for NFAT FasL-DNA binding activities. Results Western blotting showed that the expressions of both FasL and NFATc protein were significantly increased in the hippocanpus of rat subjected to transient forebrain ischemia in comparison with those of the sham control group, which were markedly reduced by CsA. The I-κB-α protein showed no changes in all groups, and phospho-I-κB-α protein was not observed in this study. Proximal and distal FasL promoter NFAT sites bind NFAT proteins from the hippocampal neurons subjected to transient forebrain ischemia, and DNA-binding activities increased significantly compared with those of the sham control group. CsA markedly inhibited these changes. Conclusion NFATc may be involved in calcineurin-mediated ischemic brain damage and transcription factor NF-κB may not be involved.