Suppression of mel18 enhances differentiation of acute myeloid leukemia cell line HL60 induced by cinnamaldehyde

AIM: To investigate the effect of suppression of mel18 gene on the differentiation of human acute myeloid leukemia cell line HL60 induced by cinnamaldehyde (CA). METHODS: HL60 cells were treated with low concentration of CA or all-trans retinoic acid (ATRA). shRNAmel18 vector and shRNALuc control vector were employed to package lentiviruses which were then used to infect HL60 cells. The virus-infected HL60 cells were treated with low concentration of CA, and ATRA was used as a positive control of differentiation-inducing agent. The differentiation markers on the cell surface and cell cycle of virus-infected HL60 cells were analyzed by flow cytometry. Western blot was used to determine the expression of MEL18, cyclin D1 and p27, as well as the phosphorylation level of Akt. RESULTS: Low concentration of CA and ATRA increased the expression of granulocytic differentiation marker CD11b on the HL60 cells, with the decreased expression of MEL18 in the HL60 cells. The expression of MEL18 decreased in shmel18 virus-infected HL60 cells (shmel18-HL60 cells), but did not change in shLuc-HL60 cells. The expression of CD11b on shmel18-HL60 cells increased with G₁-phase arrest, which went even higher after treatment with CA. The phosphorylation level of Akt and the expression of cyclin D1 decreased in shmel18-HL60 cells with the increase in the expression of p27. CONCLUSION: Inhibition of mel18 gene leads HL60 cell granulocytic differentiation. mel18 gene may affect the differentiation of HL60 cells by regulating cyclin D1 and p27 via PI3K/Akt signaling pathway. PI3K/Akt signaling pathway is also involved in CA-induced differentiation of HL60 cells by suppressing mel18 gene expression.     

Construction and in vitro analysis of recombinant adenovirus vector carrying red fluorescent protein reporter gene

AIM: To provide important tools for gene therapy and gene vaccine research by constructing an adenovirus vector containing red fluorescent protein ( RFP ) reporter gene with the approach of in vitro recombinant ligation. METHODS: The RFP gene fragment of pTurboRFP-N was digested and ligated into pShuttle transfer vector to construct recombinant vector pShuttle-TurboRFP-N. I- Ceu I/PI- Sce I were used to double digest recombinant vector pShuttle-TurboRFP-N and backbone of vector pH5'040.pkGFP-II. The target fragment was collected and ligated, and recombinant adenovirus vector AdH5'.040.CMV.RFP-N was obtained. After linearization, the vector was transfected into AD293 cells by liposome for virus packaging. The efficiency of virus packaging and RFP expression level in AD293 cells were examined using fluorescent microscope. In addition, the biological activity and titer of the virus were tested. Human lung cancer cell line A549 and breast cancer cell line MDA-MB-231 were infected with recombinant adenovirus vector AdH5'.040.CMV.RFP-N and control adenovirus vector AdH5.CMV.EGFP respectively. The infection efficiencies of the 2 vectors to different cell lines were compared by evaluating the expression levels of RFP and enhanced green fluorescent protein (EGFP). RESULTS: The recombinant adenovirus vector AdH5'.040.CMV.RFP-N was correctly constructed and confirmed by enzyme digestion. The virus was packaged by the vector in AD293 cells and had the ability to infect the target cells. The target gene in eukaryotic cells was also expressed. The number of recombinant adenoviruses and the titer of the virus after amplification and purification were 3.6×10¹⁵ vp/L and 1×10¹³ pfu/L,respectively. The infection efficiencies of recombinant adenovirus vector Ad5'.040.CMV.RFP-N to human lung cancer cell line A549 and breast cancer cell line MDA-MB-231 were higher than those in control adenovirus vector AdH5.CMV.EGFP (P<0.05). CONCLUSION: We have constructed recombinant virus vector carrying RFP reporter gene and provide an important tool for gene therapy and gene vaccine research. The reporter gene can be highly expressed in AD293 cells and has high infection efficiency to cancer cells. RFP is a good substitution and supplement to green fluorescent protein.     

Enhancement effect of adenovirus mediated antisense c-myc gene and caffeine on chemotherapy of osteosarcoma cells to cisplatin

AIM: The cancer biology has showed that overexpression of oncogenes is responsible for the progression of human malignancies,antisense technology can block a certain gene expression.Caffeine has enhancement effect on chemotherapy of osteosarcoma cells to cisplatin,we constructed the recombinant adenovirus (Ad-Asc-myc) encoding antisense c-myc fragment and investigated its effect on the in vitro sensitivity of osteosarcoma MG-63 cells to cisplatin.METHODS: The recombinant adenovirus (Ad-Asc-myc) encoding antisense c-myc fragment was constructed by cloning c-myc cDNA of about 750 base pairs in a reverse direction into adenovirus vector.Ad-Asc-myc and caffeine was used respectively or together to co-operate with cisplatin to treat the osteosarcoma MG-63 cells in vitro,and Western blotting,MTT,flow cytometry (FCM),electron microscope were used to evaluate expression of c-Myc protein,tumor cell proliferation in vitro,apoptosis and cell cycle analysis.RESULTS: Ad-Asc-myc was obtained with the titer of 2×10¹² pfu/L.Ad-Asc-myc down-regulated the expression of c-Myc protein,Ad-Asc-myc or caffeine enhanced the effects of 2.0,5.0 mg/L cisplatin on MG-63 cells.Moreover,Ad-Asc-myc combined with caffeine significantly enhanced this effects,not only on cisplatin-induced apoptosis,but also on tumor cells proliferation in vitro.The expression of bcl-2 was downregulated,bax were upregulated,while there was no change in the expression of E2F-1.FCM analysis showed that cisplatin treatment induced a block in S phase,and caffeine reversed this block and speeded up the progression of cells out of the S phase.Ad-Asc-myc induced obvious G₂/M phase arrest in transfected cells.CONCLUSION: Ad-Asc-myc combined with caffeine may enhance apoptosis-induced and chemotherapy effects of osteosarcoma MG-63 cells to cisplatin.     

Construction of recombinant adenovirus expressing BDNF and its expression in expanded rat mesenchymal stem cells in vitro

AIM:To construct recombinant adenovirus vector containing brain derived neurotrophic factor, (BDNF) gene using bacterial homogenous recombination, and investigate the expression in expanded rat mesenchymal stem cells (rMSC) in vitro.METHODS:BDNF gene and proBDNF gene were subcloned into adenovirus shuttle plasmid pAdTrack-CMV containing enhanced green fluorescent protein gene (EGFP) expression cassette, forming shuttle vector of pAdTrack-BDNF, and pAdTrack-proBDNF, and co-transformed into BJ5183 bacterial cells with adenovirus backbone vector pAdEasy-1 using chemical transformation. After the recombinant adenovirus vector was obtained, the identified recombinant adenovirus plasmid DNA was digested with Pac I and transfected to 293 cells to package recombinant adenovirus particles. rMSC were infected by recombinant adenovirus and EGFP expression was detected using fluorescent microscope. Infection efficiency was assessed by flow cytometrics. Western blotting identified expression of Ad -proBDNF and Ad-BDNF in rMSC. rMSC infected with Ad -proBDNF and Ad-BDNF were induced to differentiate into neuron-like cells. rMSC infected with Ad -proBDNF and Ad-BDNF were injected into nude mice and assessd in vivo.RESULTS:We successfully constructed the recombinant adenovirus Ad -proBDNF and Ad-BDNF that expressed in expanded rMSC in vitro.CONCLUSION:Recombinant adenovirus high-effectively mediates Ad -proBDNF and Ad-BDNF expression in expanded rMSC in vitro and in vivo.     

Protective effect of curcumin on ERS-induced NASH rat hepatocytes

AIM: To investigate whether curcumin reduces hepatocyte apoptosis in the rats with non-alcoholic steatohepatitis (NASH) by inhibiting endoplasmic reticulum stress (ERS) and thus exerting a protective effect on the liver. METHODS: Male SD rats (n=30) were randomly divided into normal control group (n=10), model group (n=10) and curcumin group (n=10). NASH model was established by feeding the rats with high-fat diet for 4 weeks. The rats in curcumin group was given curcumin (200 mg/kg) daily by gavage, while the rats in model group and normal control group were given the same volume of saline. Four weeks later, the rats were killed, and their blood and liver tissues were collected. The serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected, liver histopathological changes were observed by HE staining, the expression of glucose-regulated protein 78 (GRP78) and C/EBP homologous protein (CHOP) was determined by Western blot, and apoptosis was detected by TUNEL method. RESULTS: Compared with normal control group, the levels of serum ALT and AST in model group were significantly increased, and the levels of serum ALT and AST in curcumin group were significantly lower than those in model group (P<0.05). At the same time, the steatosis and inflammation of hepatocytes in curcumin group were less than those in model group, and no obvious necrosis was observed. Compared with normal control group, the protein expression levels of GRP78 and CHOP in model group were increased, while the protein expression levels of GRP78 and CHOP in curcumin group were decreased compared with model group (P<0.01). TUNEL results showed that apoptotic hepatocytes in model group were significantly more than those in normal control group, while those in curcumin group were significantly fewer than those in model group. CONCLUSION: Hyperlipidemia induces excessive ERS in the hepatocytes, thus triggering apoptosis and leading to NASH. The mechanism of curcumin reducing hepatocyte apoptosis may be related to its inhibition of ERS.     

Dendritic cells transfected with recombinant adenovirus carrying IL-24 gene induces CTLs to promote apoptosis of cervical cancer cell line CaSki

AIM：To investigate the therapeutic potential of interleukin-24 (IL-24) in cancer treatment, we observed the inductive effect of cytotoxic T-lymphocytes (CTLs) against human cervical cancer cell line CaSki using dendritic cells (DCs) transfected with recombinant adenovirus carrying IL-24 gene (Ad-IL-24-DCs). METHODS：Immature mouse DCs were isolated and cultured. The DCs were infected with recombinant adenovirus carrying IL-24 gene. The CaSki cell lysate-loaded autologous DCs vaccine was also prepared. The cell proliferation was analyzed by MTT assay. The cell apoptosis was determined by flow cytometry with PE-Annexin V staining. The cleaved caspase-3 in the Ad-IL-24-DCs was measured by Western blotting. Colony-forming assay was used to detect the colony number of Ad-IL-24-DCs. The tumorigenic capacity of CaSki cells in vivo in the presence of Ad-IL-24-DCs was observed by tumor-burdened model. RESULTS：IL-24 was highly expressed in the Ad-IL-24-DCs. In the presence of Ad-IL-24-DCs, the apoptosis of CaSki cells was significant increased. Additionally, the protein level of cleaved caspase-3 was increased in CaSki cells in the presence of Ad-IL-24-DCs, suggesting that the CaSki cells with Ad-IL-24-DCs induced apoptosis. CTLs induced by Ad-IL-24-DCs inhibited the tumorigenic capacity of CaSKi cells in vivo. CONCLUSION：Genetically modified DCs are successfully prepared by infection with Ad-IL-24 and show a significant effect on triggering specific CTLs against CaSki cells.     

In vitro perfusion method during cardiac graft preservation and its application in adenovirus mediated gene transfection

AIM: To establish a method of in vitro donor heart perfusion in murine cardiac transplantation during preservation and apply it in adenovirus mediated gene transfection for donor heart. METHODS: Donor heart was transfected with recombinant adenovirus and stored for 2 hours after harvest, then it was transplanted heterotopically in abdomen. The grafts were appraisal by palpitation. Marked gene products were determined by X-Gal staining, and T cell infiltration was determined by immunohistochemistry. The activation markers of recipients' lymphocytes were examed by cytometry. RESULTS: The grafts survival rate is 100% after perfusion and cold storage. The LacZ staining became strong 1 week after transplantation. The grafts remained an intact structure and no apparent T cell infiltration. The activation status of recipients' lymphocytes were not enhanced by transfected cardiac graft. CONCLUSION: In vitro perfusion during graft cold preservation is feasible for adenovirus mediated gene transfection.     

Preparation of gfp-bcl-XL-contained recombinant adenovirus vector by the homologous recombination in bacteria

AIM: To prepare gfp-bcl-X_L-contained recombinant adenovirus(rAd-gfp-bcl-X_L).METHODS: Bcl-X_L gene was amplified from pEGFP-C₃-bcl-X_L, subcloned into shuttle plasmid and formed transfer plasmid of pAdTrack-CMV-bcl-X_L. Then pAdTrack-CMV-bcl-X_L was linealinzed with PmeI and co-transformed into BJ5183 bacteria with adenovirus genomic plasmid of pAdEasy-1. The identified recombinant adenovirus plasmid was digested with PacI and transfected into 293 cells to package recombinant adenovirus particles. The target gene was detected by PCR.RESULTS: There were about 35% positive recombinant bacterial clones after the co-transformation of pAdTrack-CMV-bcl-X_L and pAdEasy-1 into BJ5183. Recombinant adenovirus particle were produced and further amplified after the transfection of pAdEasy-1-gfp-bcl-X_L into 293 cells. PCR test indicated that the recombinant Ad contained bcl-X_L gene. The titer of the purified rAd-gfp-bcl-X_L was 6.5×10¹² PFU/L. CONCLUSIONS: The homologous recombination in bacteria is a convenient and high efficient method to prepare rAd-gfp-bcl-X_L. This affords a good gene transfer vector for the gene therapy in human’s diseases.     

Anti-Sonic hedgehog blocking antibody enhances killing effect of PBMCs on cervical carcinoma HeLa cells

AIM: To investigate the effect of anti-Sonic hedgehog(Shh) blocking antibody on the killing effect of peripheral blood mononuclear cells(PBMCs) on cervical carcinoma HeLa cells. METHODS: The expression levels of Shh and Shh signaling molecules in HeLa cells were detected by immunocytochemistry and RT-PCR. PBMCs from health peoples were isolated by the method of Ficoll density gradient centrifugation, and then co-cultured with HeLa cells in vitro. The expression of CD3, CD69 and CD71 was assayed by flew cytometry. The concentrations of IFN-γ, IL-10 and IL-4 in culture supernatants were detected by ELISA. The killing effect of PBMCs on HeLa cells was observed under microscope. RESULTS: Shh and Shh signaling molecules were expressed in HeLa cells. The level of Shh expression didn't change significantly in the 6th passage of HeLa cells. CD3⁺ cells were increased in the co-culture system. The expression of CD69 and CD 71, and the secretion of IFN-γ were increased, while the secretion of IL-10 was decreased in the co-culture system treated with anti-Shh blocking antibody. Anti-Shh blocking antibody has no effect on the secretion of IL-4. The killing effect of PBMCs on HeLa cells was strengthened by anti-Shh blocking antibody. CONCLUSION: Anti-Shh blocking antibody promotes the activation of PBMCs and enhances the killing effect of PBMCs on cervical carcinoma HeLa cells.     

Lipotoxicity of free fatty acid mixture and effect of free fatty acid mixture on lipid metabolism-related genes in L-02 cells

AIM：To investigate the lipotoxicity of free fatty acid (FFA) mixture and the effect of the FFA mixture on lipid metabolism-related genes in L-02 cells. METHODS：A normal human hepatocytes-derived cell line L-02 was treated with 0.5, 1 and 2 mmol/L FFA mixture (oleate and palmitate, 2∶1) for 24 h. The cellular total lipid accumulation was determined after Nile red staining by confocal laser scanning microscopy and flow cytometry. Intracellular triglyceride (TG) content was measured using an enzymatic kit. The viability of L-02 cells was determined by MTT assay and the apoptosis-inducing effect of FFA mixture was evaluated by annexin V/PI staining. The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the culture medium were detected by ALT and AST kits. The mRNA levels of lipid metabolism-related genes, adipose differentiation-related protein (ADRP) and sterol regulatory element-binding protein 1 (SREBP-1), were examined by quantitative real-time PCR. RESULTS：All the different concentrations of FFA mixture increased intracellular lipid accumulation and TG content in a dose-dependent manner. FFA mixture at concentration of 1 mmol/L increased intracellular TG by 2.6 folds, which matched with the change in non-alcoholic fatty liver disease patients. Treatment for 24 h with 0.5 mmol/L and 1 mmol/L FFA mixture did not trigger apparent cell death and apoptosis, while treatment with 2 mmol/L FFA mixture resulted in a marked decrease in cell viability and induced early and late stages of apoptosis in L-02 cells. The levels of ALT and AST in the culture supernatant had no significant difference between control group and FFA treatment group. Treatment with 1 mmol/L FFA mixture up-regulated the expression of ADRP and SREBP-1 by 2.660 and 2.758 folds, respectively. CONCLUSION：FFA mixture induces the hepatic steatosis and 2 mmol/L FFA mixture causes mild cells damage in L-02 cells. The up-regulation of ADRP and SREBP-1 may be involved in FFA-induced hepatic steatosis.     

Proliferative effect of PDGF and anti-proliferative activity of AMPK on vascular smooth muscle cells

AIM: To investigate the proliferative effect of platelet-derived growth factor (PDGF) and anti-proliferative activity of AMP-activated protein kinase (AMPK) on vascular smooth muscle cells (VSMCs). METHODS: The proliferation of VSMCs cultured with PDGF and activation of AMPK were observed. VSMCs were divided in 4 groups: control group; PDGF group; 5-aminoimidazole-4 -carboxamide-1-β-D-riboside (AICAR) group and AICAR+PDGF group. The time course of AMPK activation was determined. The protein level of mTOR was also measured. RESULTS: Compared with control group, the proliferative rate in PDGF group was significantly increased. The growth of VSMCs was inhibited in a time-dependent manner and the activity of p-mTOR was significantly decreased in AICAR group. Compared with control group, the expression of p-AMPK in PDGF group was significantly decreased, and that in AICAR group and AICAR+PDGF group was significantly increased. The expression of p-AMPK in AICAR+PDGF group was higher than that in PDGF group. The activity of p-mTOR in PDGF group was significantly higher than that in control group, while that of AICAR group and AICAR+PDGF group was significantly decreased. The expression of p-mTOR in AICAR+PDGF group was lower than that in PDGF group. CONCLUSION: Stimulation of VSMCs with PDGF promotes the cell proliferation, which can be inhibited by AICAR. The proliferation of VSMCs activated by AMPK is probably correlated with the down-regulation of mTOR expression.     

Construction of shRNA targeting AGR2 gene and effect of AGR2 on biological function of nasopharyngeal carcinoma cells

AIM: To construct the shRNA targeting anterior gradient protein 2 (AGR2) gene for exploring the effect of AGR2 on the biological behavior of nasopharyngeal carcinoma (NPC) cells.METHODS: The expression of AGR2 at mRNA and protein levels in NPC cell lines 6-10B and 5-8F was detected by real-time PCR and Western blot. The pSR-GFP/Neo-AGR2-shRNA expression vector targeting AGR2 was constructed. Based on the interference targeting AGR2, the cell migration and motility were determined by Transwell migration and motility assays.RESULTS: The expression of AGR2 was increased in NPC cell line 5-8F compared with NPC cell line 6-10B (P<0.05). When the AGR2 expression in 5-8F cells was interfered, the cell migration, invasion and tumorigenicity were weakened.CONCLUSION: The expression of AGR2 is up-regulated in NPC cell line 5-8F. pSR-GFP/Neo-CLU-shRNA successfully inhibits the expression of AGR2 in NPC cell line 5-8F. AGR2 inhibits the migration, invasion and tumorigenicity of 5-8F cells in vivo.     

Molecular simulation and experimental study on role of BRAF in anti-melanoma effect of 10-gingerol

AIM:To investigate the role of BRAF protein in the anti-melanoma effect of 10-gingerol (10-G) by molecular simulation techniques and cell experiments. METHODS:Human skin melanoma A375 cells were induced by 10-G (10, 20 and 40 μmol/L) for 24 h. The cell viability was measured by MTS assay and cell counting. The interaction between 10-G and BRAF protein was analyzed by molecular docking and molecular dynamics simulations. The protein levels of p-BRAF, BRAF, p-MEK1/2, p-ERK1/2 and p-P38 were determined by Western blot. RESULTS:Treatment with 10-G significantly reduced the cell viability and cell number in a dose-dependent manner (P<0.01). The binding energy between 10-G and wild-type BRAF was -7.358 kcal/mol, and that between 10-G and V600E mutant BRAF (BRAF^V600E) was -8.255 kcal/mol. Molecular dynamics simulations confirmed that the binding between BRAF^V600E and 10-G was stable. The protein levels of p-BRAF, p-MEK1/2 and p-P38 in the A375 cells was significantly reduced by 10-G (P<0.01), while the protein level of p-ERK1/2 was unchanged. CONCLUSION:The viability of melanoma cells is significantly inhibited by 10-G. The mechanism might be related to the inhibition of BRAF activation.     

Mechanism underlying the antagonistic effect of folic acid on homocysteine-induced apoptosis in endothelial cell

AIM: To investigate the effects of homocysteine (Hcy) on apoptosis in SV40-transformed aortic rat endothelial cell line and the anti-apoptosis effects of folic acid. METHODS: Cells were treated with different concentrations of Hcy and folic acid, apoptosis was detected by TUNEL and annexin-V/ PI staining methods. Immunohistochemical assay was used to examine the expression of Bax and Bcl-2 in all groups. RESULTS: Both annexin-V/PI staining and TUNEL method showed that Hcy increased endothelial apoptosis in a dose-dependent manner, while folic acid reduced cell apoptosis. Hcy increased expression of Bax and Bcl-2 in endothelial cells, and folic acid decreased it. Bax/Bcl-2 ratio in 0.5 mmol/L Hcy and 5.0 mmol/L Hcy group were upregulated compared with control group (P<0.05 and P<0.01, respectively). Addition of 0.1 mmol/L folic acid decreased Bax/Bcl-2 ratio compared with the corresponding group without folic acid (P<0.05). Correlation analysis showed a strong relation between Bax/Bcl-2 ratio and apoptotic rate (P<0.01). CONCLUSION: Folic acid attenuates the apoptosis induced by Hcy in endothelial cells. Hcy may promote endothelial cell apoptosis via upregulation of Bax /Bcl-2 ratio, which can be partially antagonized by folic acid.     

Inhibitory effect of sodium ferulate on Aβ25-35-induced p38 MAPK activation

AIM: To investigate effect of sodium ferulate on Aβ_25-35-mediated signaling pathway. METHODS:The isolated peritoneal macrophages from mice were cultured. p38 MAPK protein kinase in nuclear extracts was analyzed by Western blotting. The concentration of TNF-α and NO in supernatant were measured by ELISA and Griess reaction technique. The expression of iNOS protein was detected by immunochemical technique. RESULTS:Aβ_25-35 significantly increased the concentrations of TNF-α and NO in supernatant, expression of iNOS in macrophages and p38 MAPK protein kinase in nuclear extracts, which were blocked by sodium ferulate. CONCLUSION:Sodium ferulate inhibits p38 MAPK activation triggered by Aβ_25-35.     

Inhibitory effect of 5-fluorouracil on ultra-microstructure and insulin secretion of pancreatic β cells

AIM: To investigate the molecular mechanisms of β cell dysfunction induced by 5-fluorouracil (5-FU) in islet β cell line (NIT-1 cells). METHODS: The NIT-1 cells were treated with different concentrations of 5-FU. The content of insulin in the culture medium was determined by radioimmunoassay. Cell apoptosis was observed by flow cytometry with annexin V/PI staining. The ultra-microstructural changes of NIT-1 cells were observed under transmission electron microscope. The expression of pancreatic and duodenal homeobox protein 1(PDX-1) at mRNA and protein levels in NIT-1 cells was examined by RT-PCR and Western blotting, respectively. RESULTS: Exposed to the low glucose concentration (5.6 mmol/L), insulin secretion in NIT-1 cells was not significantly decreased following a 24 h treatment with 5.0 to 40.0 mg/L 5-FU (P>0.05). On the contrary, the high glucose (16.7 mmol/L)-stimulated insulin secretion in NIT-1 cells was inhibited by 5.0 to 40.0 mg/L of 5-FU in a dose-dependent manner after 24 h of incubation (P<0.01). The apoptosis rate of NIT-1 cells was significantly increased as compared to those in the control levels(P<0.05). The structural changes of mitochondria were the main apoptotic changes under transmission electron microscope. Significant down-regulation of PDX-1 expression at mRNA and protein levels was observed in NIT-1 cells treated with 5-FU at the concentration of 10.0 mg/L to 40.0 mg/L(P<0.05).CONCLUSION: 5-FU inhibits the insulin secretion in islet β cell induced by high glucose. A relative deficiency in insulin secretion following 5-FU treatment is related to the changes of β cell ultra-microstructure and the reduction of β cell numbers, by which an increase in apoptosis of pancreatic β cells is induced. Down-regulation of PDX-1 expression may play a pivotal role in increasing the apoptosis of pancreatic β cells induced by 5-FU in high-glucose condition.     

Inhibitory effect of oxymatrine on high glucose-induced rat renal tubular epithelial-mesenchymal transition

AIM:To investigate the inhibitory effect of oxymatrine (OM) on high glucose-induced rat renal tubular epithelial-mesenchymal transition (EMT). METHODS:The rat renal tubular epithelial NRK52E cells were cultured in vitro. The cells were divided into control group, high glucose group, high glucose+different concentrations of OM groups and high glucose+0.50 g/L OM dynamic observation group. The expression of TGF-β1, Smad7, α-SMA and E-cadherin at mRNA and protein levels was detected by real-time PCR and Western blotting. The viability of NRK52E cells was determined by MTT assay. RESULTS:(1) Compared with control group, the expression of TGF-β1 and α-SMA at mRNA and protein levels in high glucose group gradually increased, and Smad7 protein and E-cadherin mRNA and protein gradually reduced, but the mRNA expression of Smad7 gradually increased. (2) Compared with high glucose group, as increases in OM doses, the expression of TGF-β1 and α-SMA at mRNA and protein levels in high glucose+different concentrations of OM groups gradually reduced, and Smad7 protein and E-cadherin mRNA and protein gradually increased, but the mRNA expression of Smad7 had no significant change. (3) Compared with high glucose group, the expression of TGF-β1 and α-SMA at mRNA and protein levels was significantly reduced, the expression of E-cadherin at mRNA and protein levels significantly increased, and the protein expression of Smad7 significantly increased, but the mRNA expression of Smad7 had no significant change in high glucose+0.50 g/L OM dynamic observation group. CONCLUSION: In NRK52E cells, oxymatrine inhibits high glucose induced EMT by down-regulating TGF-β1 and up-regulating Smad7, thus preventing the fibrosis effect of TGF-β1/Smads signaling.     

Protective effect of morinda officinalis oligosaccharides monomer HexB on hypoxia/reoxygenation-induced injury in HUVECs

AIM:To explore the protective effect of morinda officinalis oligosaccharides monomer HexB on hypoxia/reoxygenation (H/R)-induced injury in human umbilical vein endothelia cells (HUVECs). METHODS:HUVECs were treated with HexB, 4-phenylbutyric acid (4-PBA) and thapsigargin (TG), respectively. The cells were divided into control group, HexB group, H/R group, HexB+H/R group, 4-PBA+H/R group, TG group and HexB+TG group. The cell viability was measured by CCK-8 assay. The apoptotic rate was detected by flow cytometry. Western blot was used to determine the protein levels of endoplasmic reticulum stress (ERS) related molecules chaperone protein glucose-regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), apoptosis-related protein caspase-12 and phosphorylated c-Jun NH₂-terminal kinase (p-JNK). RESULTS:The viability of HUVECs was reduced in H/R group and TG group (P<0.05), increased in HexB+H/R, 4-PBA+H/R and HexB+TG group (P<0.05). The apoptotic rate, the protein levels of GRP78, CHOP, caspase-12 and p-JNK were increased in H/R group and TG group (P<0.05), weakened in the HexB+H/R group (P<0.05), 4-PBA+H/R group and HexB+TG group (P<0.05). No significant change in the apoptotic rate, cell viability, protein levels of GRP78, CHOP, caspase-12, p-JNK between HexB+H/R group and 4-PBA+H/R group was observed. CONCLUSION:HexB attenuates HUVECs injury caused by H/R through suppressing ERS and apoptosis. The possible mechanism may be involved in the apoptotic pathways related to GRP78, CHOP, caspase-12 and p-JNK.     

Protective effect of anti-aging Klotho protein on human umbilical vein endothelial cells treated with high glucose

AIM: To study the protective effect of anti-aging Klotho protein on human umbilical vein endothelial cells (HUVECs) treated with high glucose (HG).METHODS: HUVECs were cultured in vitro, and divided into PBS control group, 5.5 mmol/L glucose group, 33.3 mmol/L glucose group, 0.1 μmol/L Klotho+33.3 mmol/L glucose group, 1 μmol/L Klotho+33.3 mmol/L glucose group, and 10 μmol/L Klotho+33.3 mmol/L glucose group. The viability of the HUVECs was measured by MTT assay. The content of malondialdehyde (MDA), and the activities of lactate dehydrogenase (LDH), superoxide dismutase (SOD) and glutathione (GSH) in cell culture supernatants were observed. The production of reactive oxygen species (ROS) in HUVECs was analyzed by flow cytometry. The levels of nitric oxide (NO), endothelin (ET-1), intercellular adhesion molecule-1 (ICAM-1) in HUVEC culture medium were detected by ELISA. The protein expression of nuclear factor-kappa B (NF-κB) in the HUVECs was determined by Western blot. RESULTS: Compared with PBS control group, 33.3 mmol/L glucose significantly decreased the HUVEC viability, increased ROS, LDH and MDA levels, reduced the activities of SOD and GSH, decreased the NO secretion, and induced the ET-1 and ICAM-1 secretion and the protein expression of NF-κB in HUVECs. When HUVECs were treated with Klotho protein at different concentrations combined with 33.3 mmol/L glucose, the cell viability was increased significantly, the ROS, LDH and MDA levels were decreased significantly, the antioxidant SOD and GSH activities were significantly increased, the secretion of NO was increased, but ET-1 and ICAM-1 releases and protein expression of NF-κB were significantly reduced.CONCLUSION: Anti-aging Klotho protein promotes the viability of HUVECs treated with HG, reduces the oxidative damage and ROS production, and restores the normal secretory function of HUVECs, thus playing a protective role in vascular endothelial cells through reducing the protein expression of NF-κB.     

Expression of CUG-binding protein 1 in breast cancer and its effect on cell viability and invasion ability

AIM: To investigate the expression of CUG-binding protein 1 (CUGBP1) in breast cancer tissues, and to explore the effect of CUGBP1 gene silencing on the viability and invasion ability of human breast cancer MCF-7 cells. METHODS: A total of 96 cases of patients with breast cancer undergoing surgical treatment were selected in the Second Affiliated Hospital of Zhengzhou University from March 2015 to September 2017. Immunohistochemical staining was used to detect the protein expression of CUGBP1 in the breast cancer and adjacent tissues. MCF-7 cells were cultured and divided into CUGBP1 interference sequence group, control sequence group and blank group. Western blot was used to detect the protein expression of CUGBP1, Twist, E-cadherin and vimentin in the cells. The cell viability was measured by MTT assay. The cell invasion ability was detected by Transwell assay. RESULTS: The positive expression rate of CUGBP1 protein in the breast cancer tissues was higher than that in the adjacent tissues (χ²=28.900, P<0.001). The differences of CUGBP1 protein expression in the breast cancer tissues among TNM staging, histological grading and lymph node metastasis were statistically significant (P<0.05). The relative protein expression levels of CUGBP1, Twist and vimentin in CUGBP1 interference sequence group were lower than those in control sequence group and blank group, while the relative protein expression of E-cadherin was higher than that in control sequence group and blank group (P<0.05). The cell viability at 24 h, 48 h, 72 h and 96 h in CUGBP1 interference sequence group was lower than that in control sequence group and blank group (〖P<0.05). The invasive cells in CUGBP1 interference sequence group were less than those in control sequence group and blank group (P<0.05). CONCLUSION: CUGBP1 protein is highly expressed in the breast cancer tissues. Specific silencing of 〖STBX〗CUGBP1〖STBZ〗 gene expression in breast cancer MCF-7 cells effectively inhibits the cell viability and invasiveness, and its mechanism may be related to inhibiting the process of epithelial-mesenchymal transition.