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Total flavonoids of Dracocephalum moldavica L. (TFDM) is an effective component extracted and isolated from the traditional Uighur medicinal herb Cymbidium fragrans. Cymbidium fragrans has the effects of tonifying the heart and brain, promoting blood circulation and resolving blood stasis, and has been widely used in the treatment of cardiovascular and cerebrovascular diseases for a long time. The purpose of this study was to determine the effect of total flavonoids from Cymbidium fragrans on hypoxia/re-oxygenation (H/R) injury in H9c2 (rat cardiomyocytes) cells and its mechanism. A model (H/R) of hypoxia/re-oxygenation injury in H9c2 cells was established using hypoxia and glucose deprivation for 9 h combined with re-oxygenation and rehydration for 2 h to simulate myocardial ischemia-reperfusion injury. The effects of total flavonoids from Cymbidium fragrans on cell viability, markers of myocardial cell damage, oxidative stress levels, and reactive oxygen radical (ROS) content were investigated, Western blot was used to detect the expression of vascular endothelial growth factor B (VEGF-B) and adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway related proteins. The results showed that the total flavonoids of Cymbidium fragrans significantly increased the viability of myocardial cells after H/R injury, and decreased the content of lactate dehydrogenase (LDH) and creatine kinase isozyme (CK-MB) in the cell supernatant. It significantly reduced malondialdehyde (MDA), increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, and decreased intracellular ROS and nitric oxide (NO) content. Western blot analysis showed that the total flavonoids of Cymbidium fragrans decreased Bax levels in H9c2 cells damaged by H/R and increased Bcl-2 expression. Total flavones of Cymbidium fragrans upregulate VEGF-B/AMPK pathway related proteins VEGF-B, vascular endothelial growth factor receptor 1 (VEGFR-1), neuropilin 1 (NRP-1), peroxisome-proliferator-activated receptor γ coactivator-1α (PGC-1α), phosphorylated adenosine monophosphate activated protein (p-AMPK) and phospho mechanistic target of rapamycin (p-MTOR) levels. The above research results indicate that the total flavonoids of Cymbidium can significantly reduce the H/R injury of myocardial cells, which may be related to the upregulation of VEGF-B/AMPK pathway and inhibition of oxidative stress response.
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Objective To investigate the protective effects of lentivirus mediated Bcl-2-associated athanogene 1L (BAG-1L) over-expression on human neuroblastoma cells (SH-SYSY) induced by hypoxia/re-oxygenation,and to study its effect on the phosphoinositide 3 kinase serine/threonine protein kinase (PI3K/AKT) pathway.Methods SH-SYSY cells were cultured in vitro,and the cells at logarithmic phase were collected,and they were divided into recombined lentiviral infection group [infected by lentivirus containing BAG-1L and green fluorescent protein (GFP) gene],vector control group (infected by lentivirus containing GFP without BAG-1L gene) and cell control group (non-infection).Western Blot was used to detect the expression of BAG-1L in target cells after infection for 48 hours.SH-SY5Y cells were subjected to hypoxia for 8 hours and re-oxygenation for 24 hours,then the cell counting kit-8(CCK-8) was used to detect the cell activity,and the apoptosis was detected by flow cytometry after allophycocyanin labeled annexin V/7-amino actinomycin D (Annexin V-APC/7-AAD) staining.Western Blot was used to detect the protein expressions of BAG-1L,heat shock protein 70 (HSP70),AKT and phosphorylated AKT (p-AKT).Results After infection for 48 hours,exogenous BAG-1L protein bands were observed in recombined lentiviral infection group,but not observed in cell control group and vector control group.After hypoxia/re-oxygenation treatment,the cell viability in recombined lentiviral infection group was significantly higher than that in cell control group and vector control group (A value:0.689 ± 0.036 vs.0.425 ± 0.013,0.400 ± 0.012),apoptosis was significantly decreased [apoptosis rate:(26.97 ± 1.82)％ vs.(36.60± 1.45)％,(35.77 ± 3.74)％],the protein levels of BAG-1L,HSP70 and p-AKT were significantly increased [BAG-1L protein (gray value):2.405 ± 0.167 vs.0.529 ± 0.141,0.601 ± 0.099;HSP70protein (gray value):0.997±0.123 vs.0.634±0.091,0.584±0.106;p-AKT protein (gray value):1.234±0.118 vs.0.661 ± 0.210,0.712 ± 0.199,all P ＜ 0.01],but the protein level of AKT was slightly increased (gray value:1.103 ± 0.269vs.0.646 ± 0.188,0.791 ± 0.326) without statistically significant differences (both P ＞ 0.05).There was no significant difference in all parameters between cell control group and vector control group (all P ＞ 0.05).Conclusion Lentivirus mediated BAG-1L gene over-expression can protect nerve cells against hypoxic injury and apoptosis,and the protective effect may be related to the activation increase of pathway on PI3K/AKT.
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Objective To investigate the migration of bone-marrow mesenchymal stem cells (BMSCs) under acute kidney injury (AKI) microenvironment in vitro and the effect of erythropoietin (EPO) intervention,and to explore its underlying mechanism.Methods Renal tubular epithelial cells (RTECs) were cultured in hypoxia/re-oxygenation (HR) condition for 12 h,respectively,in order to establish HR-RTEC.BMSCs and RTECs were co-cultured by Transwell system and were divided into 7 groups:control group (group①,only BMSC cultured),BMSC-RTEC co-culturing group (group ②),BMSC-HR-RTEC co-culturing + EPO intervention groups (group ③to group ⑦,EPO concentration:0,1,5,10,50 IU/ml).All the groups were cultured for 48 h and the number of migrating BMSCs was detected.Western blotting was applied for the detection of SDF-1 expression in RTECs and pMAPK and MAPK levels in BMSCs.SDF-1 concentration in the RTECs culture supernatant was tested by ELISA.Results The number of BMSCs migrating to the low chamber where HR-RTECs were cultured was increased,and EPO intervention further enhanced this migration which reached the peak at the concentration of 10 IU/ml [Compared with group③,(46.67±7.37) cells vs (19.00±2.37) cells,P ＜ 0.05].Intracellular expression level and the secreated level of SDF-1 in HR-RTECs in group③ were higher than those in RTECs of group② [0.37±0.01 vs 0.19±0.01,P ＜ 0.05; (61.64±4.88) μg/L vs (35.26±8.78) μg/L,P ＜ 0.05].EPO intervention increased above SDF-1 levels and reached the peak at the concentration of 10 IU/ml [group⑥ vs group③:(173.53± 14.66) μg/L vs (61.64±4.88) μg/L,P＜0.05],accompanied with enhanced phosphorylation of MAPK in BMSCs.Conclusions AKI microenvironment has obvious chemotaxis effect on BMSCs,and EPO intervention can strengthen this effect.The increased SDF-1 level and enhanced phosphorylation of MAPK,the downstream signal protein of SDF-1/CXCR4 axis,are the possible mechanism for EPO performance.
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Objective CXCR4-overexpressing bone marrow-derived mesenchymal stem cells (CXCR4-BMSC) were constructed and co-cultured with hypoxia/re-oxygenation pretreated renal tubular epithelial cells (HR-RTEC).Repair of HR-RTEC was detected and the possible mechanism was also discussed.Methods CXCR4-BMSC (CXCR4-BMSC/eGFP,eGFP as the tracer gene) and null-BMSC (BMSC/eGFP) were obtained by gene transfection technique,and the level of CXCR4 in the transfected cells was detected.RTEC was cultured under hypoxia/re-oxygenation condition for 12 h,respectively,to obtain HR-RTEC,which was used to simulate AKI in vitro.BMSC and HR-RTEC were co-cultured for 12 h,and the proportion of apoptotic cells among the HR-RTEC was assayed by immunofluorescence technique.Western blot was used to test the protein levels of cleaved Caspase-3 and Bcl-2.The number of migrating BMSC was also assayed.After culturing with the HR-RTEC culture supernatant,the expression of cytokeratin 18 (CK18) in BMSC was tested by immunofluorescence staining.Cytokines including bone morphogenetic protein-7 (BMP-7),hepatic growth factor (HGF) and interleukin-10 (IL-10) in the BMSC culture supernatant were detected by ELISA method.Results Expression of CXCR4 was enhanced in CXCR4-BMSC.Proportions of the apoptotic cells among HR-RTEC after being co-cultured with BMSC,CXCR4-BMSC and null-BMSC were all decreased,especially in the C/H group.The decreased cleaved Caspase-3 and enhanced Bcl-2 were also observed in HR-RTEC.The number of migrating CXCR4-BMSC was the highest.Proportions of CK18+ cells in BMSC,CXCR4-BMSC and null-BMSC were all low and showed no difference.However,CXCR4 overexpression in BMSC stimulated secretions of BMP-7,HGF and IL-10.Conclusions CXCR4-overexpressing BMSC has more repair effect on the co-cultured HR-RTEC,the enhanced migration ability and secretion ability of CXCR4-BMSC are the possible mechanisms.