ObjectiveTo observe the effects of four prostaglandin E2 (PGE2) receptors (EP1-4R) on the activation of inflammasomes and cell damage in human retinal microvascular endothelial cells (hRMEC) in a high glucose environment.MethodsThe hRMEC were divided into normal group and high glucose group, and they were cultured in Dulbecco modified Eagle medium containing 5.5 and 30.0 mmol/L glucose, respectively. Flow cytometry was used to observe the apoptosis rate of the high glucose group and the normal group; enzyme chain immunosorbent assay (ELISA) was used to detect the level of PGE2 in the culture supernatant of hRMEC cells. Western blot was used to detect the protein expression of cyclooxyganese (COX2) and EP1-4R in hRMEC. Real-time fluorescent quantitative polymerase chain reaction (qRT-PCR) was used to detect the expression of EP1-4R mRNA in hRMEC. After 72 h of culture, the cells in the high glucose group were divided into control group, PGE2 group, EP1-4R agonist group, PGE2+EP1-4R inhibitor group, and dimethylsulfoxide group. According to the group, each group was given the corresponding agonist or inhibitor to continue the culture for 24 h. QRT-PCR was used to detect the expression of nucleotide-binding oligomerization structure-like receptor protein (NLRP3) and pro-interleukin (IL)-1β mRNA in each group of cells. ELISA was used to detect the content of IL-1β and lactic dehydrogenase (LDH) in the cell culture supernatant. Western blot was used to detect the expression of cleaved Caspase-1 in each group of cells. At the same time, hRMEC in a high glucose environment was given IL-1β stimulation for 24 h, and the activity of LDH in the supernatant of the cell culture medium was detected.ResultsThe apoptotic rate, COX2 protein expression, and PGE2 protein content in hRMEC in the high glucose group were significantly higher than those in the normal group, and they were time-dependent. Compared with the normal group, the expression levels of EP1R, EP2R, EP4R protein and mRNA in hRMEC in the high glucose group were higher than those in the normal group (P＜0.05). Compared with the control group, PGE2 group (t=4.627, P＜0.01), EP1-4R agonist group (t=3.889, 3.583, 2.445, 3.216; P＜0.05) hRMEC NLRP3 mRNA expression level was significantly increased; the expression level of pro-IL-1β mRNA increased, however the difference was not statistically significant (PGE2 group: t=1.807, P＞0.05; EP1-4R agonist group: t=1.807, 1.477, 0.302, 1.926, P＞0.05). Compared with the PGE2 group, the expression of NLRP3 mRNA in hRMEC in the PGE2+EP2R inhibitor group was significantly reduced (t=2.812, P＜0.05); the expression of pro-IL-1β mRNA in hRMEC in the PGE2+EP3R inhibitor group was significantly increased (t=4.113, P＜0.01). The protein content of IL-1β in the cell culture supernatant of the PGE2 group, EP1R agonist group and EP2R agonist group was significantly higher than that of the control group (t=5.155, 4.136, 4.817; P＜0.01). Compared with PGE2 group, the protein content of IL-1β in the cell culture supernatant of the PGE2+EP2R inhibitor group and the PGE2+EP4R inhibitor group were significantly lower than that of the PGE2 group (t=1.964, 4.765; P＜0.05). The expression of cleaved Caspase-1 in hRMEC in the PGE2 group and EP2R agonist group was significantly higher than that in the control group (t=5.332, 4.889; P＜0.05). The expression of cleaved Caspase-1 in hRMEC in the PGE2+EP2R inhibitor group was significantly lower than that of the PGE2 group (t=6.699, P＜0.01). The LDH activity in the cell culture supernatant of the PGE2 group and the EP2R agonist group was significantly higher than that of the control group (t=4.908, 4.225; P＜0.05). The activity of LDH in the cell culture supernatant of the PGE2+EP2R inhibitor group was significantly lower than that of the PGE2 group (t=5.301, P＜0.01). Compared with the control group, the LDH activity in the culture supernatant of hRMEC cells in the high glucose environment was significantly increased (t=3.499, P＜0.05).ConclusionsThe four receptors of PGE2 can activate NLRP3 and its effector molecules to varying degrees. EP2R mainly mediates hRMEC damage under high glucose environment.
ObjectiveTo evaluate the effects of icariin on autophagy induced by low-concentration of glucocorticoid and exosome production in bone microvascular endothelial cells (BMECs).MethodsBMECs were isolated from femoral heads resected in total hip arthroplasty and then intervened with hydrocortisone of low concentration (0, 0.03, 0.06, 0.10 mg/mL), which were set as groups A, B, C, and D, respectively. On the basis of hydrocortisone intervention, 5×10?5 mol/L of icariin was added to each group (set as groups A1, B1, C1 and D1, respectively). Western blot was used to detect the expressions of microtubule-associated protein 1 light chain 3B (LC3B) and dead bone slice 1 (p62) after 24 hours. Exosomes were extracted from BMECs treated with icariin (intervention group) and without icariin (non-intervention group), and the diameter and concentration of exosomes were evaluated by nanoparticle tracking analysis technique. The total protein content of exosomes was detected by BCA method, and the expressions of proteins carried by exosomes including CD9, CD81, transforming growth factor β1 (TGF-β1), and vascular endothelial growth factor A (VEGFA) were assessed by Western blot. The BMECs were further divided into three groups: BMECs in the experimental group and the control group were co-cultured with exosomes secreted by BMECs treated with or without icariin, respectively; the blank control group was BMECs without exosome intervention. The three groups were treated with hydrocortisone and Western blot was used to detect the expressions of LC3B and p62. The scratching assay was used to detect cell migration ability; angiogenic ability of BMECs was also assessed.ResultsWith the increase of hydrocortisone concentration, the protein expression of LC3B-Ⅱ increased gradually, and the protein expression of p62 decreased gradually (P<0.01). Compared with group with same concentration of hydrocortisone, the protein expression of LC3B-Ⅱ decreased and the protein expression of p62 increased after the administration of icariin (P<0.01). The concentration of exosomes in the intervention group was significantly higher than that in the non-intervention group (t=?10.191, P=0.001); and there was no significant difference in exosome diameter and total protein content between the two groups (P>0.05). CD9 and CD81 proteins were highly expressed in the non-intervention group and the intervention group, and the relative expression ratios of VEGFA/CD9 and TGF-β1/CD9 proteins in the intervention group were significantly higher than those in the non-intervention group (P<0.01). After co-culture of exosomes, the protein expression of p62 increased in blank control group, control group, and experimental group, while the protein expression of LC3B-Ⅱ decreased. There were significant differences among groups (P<0.05). When treated with hydrocortisone for 12 and 24 hours, the scratch closure rate of the control group and experimental group was significantly higher than that of the blank control group (P<0.05), and the scratch closure rate of the experimental group was significantly higher than that of the control group (P<0.05). When treated with hydrocortisone for 4 and 8 hours, the number of lumens, number of sprouting vessels, and length of tubule branches in the experimental group and the control group were significantly greater than those in the blank control group (P<0.05); the length of tubule branches and the number of lumens in the experimental group were significantly greater than those in the control group (P<0.05).ConclusionIcariin and BMECs-derived exosomes can improve the autophagy of BMECs induced by low concentration of glucocorticoid.
Objective To investigate the relationship of cluster of differentiation 40L (CD40L) between inflammatory response mediated by vascular endothelial injury and Stanford A type aortic dissection (STAAD). Methods In this study from August 2016 to February 2017, a total of 215 blood samples from 95 STAAD patients (67 males and 28 females aged 48.33±12.19 years) and 120 healthy volunteers (94 males and 26 females aged 48.64±10.13 years) were collected. The patients with aortic dissection were taken blood 1 hour before the operation and the healthy volunteers were taken blood from the elbow vein. All STAAD patients were diagnozed by computed tomography angiography (CTA) and patients with Marfan syndrome were excluded. Blood samples were tested by enzyme-linked immunosorbent assay (ELISA) for CD40L, vascular cell adhesion molecule (VCAM-1), E-selectin, interleukin-1 (IL-1) beta, IL-6, tumor necrosis factor-alpha (TNF-α) and so on. ResultsCompared with the healthy population, the level of SCD40L(26.87±5.50 ng/ml vs. 13.39±4.03 ng/ml, P<0.001) in the STAAD patients was significantly higher. E-Selectin (116.62±25.24 ng/ml vs. 77.05±14.30 ng/ml, P<0.001), VCAM-1 (P<0.001), TNF-α (55.35±9.12 ng/ml vs. 37.33±5.61 pg/ml, P<0.001), IL-1β (62.12±13.37 ng/ml vs. 48.68±9.86 pg/ml, P<0.001), IL-6 (499.54±90.45 ng/ml vs. 422.44±34.00 pg/ml, P<0.001) significantly increased. Conclusion The increased expression of SCD40L in STAAD patients and the inflammatory reaction induced by endothelial injury in aortic dissection patients are obvious.
Coronary atherosclerotic heart disease is a serious threat to human life and health. In recent years, the main treatment for it is to implant the intravascular stent into the lesion to support blood vessels and reconstruct blood supply. However, a large number of experimental results showed that mechanical injury and anti-proliferative drugs caused great damage after stent implantation, and increased in-stent restenosis and late thrombosis risk. Thus, maintaining the integrity and normal function of the endothelium can significantly reduce the rate of thrombosis and restenosis. Stem cell mobilization, homing, differentiation and proliferation are the main mechanisms of endothelial repair after vascular stent implantation. Vascular factor and mechanical microenvironmental changes in implanted sites have a certain effect on re-endothelialization. In this paper, the process of injury caused by stent implantation, the repair mechanism after injury and its influencing factors are expounded in detail. And repairing strategies are analyzed and summarized. This review provides a reference for overcoming the in-stent restenosis, endothelialization delay and late thrombosis during the interventional treatment, as well as for designing drug-eluting and biodegradation stents.
Objective To investigate the effect of Nodal protein on retinal neovascularization under hypoxia. MethodsIn vivo animal experiment: 48 healthy C57BL/6J mice were randomly divided into normal group, oxygen-induced retinopathy (OIR) group, OIR+dimethyl sulfoxide (DMSO) group and OIR+SB431542 group, with 12 mice in each group. Retinal neovascularization was observed in mice at 17 days of age by retina flat mount. Counts exceeded the number of vascular endothelial nuclei in the retinal inner boundary membrane (ILM) by hematoxylin eosin staining. In vivo cell experiment: human retinal microvascular endothelial cells (hRMEC) were divided into normal group, hypoxia group, hypoxia+DMSO group and hypoxia +SB431542 group. The cell proliferation was detected by thiazolyl blue colorimetry (MTT). The effect of SB431542 on hRMEC lumen formation was detected by Matrigel three-dimensional in vitro molding method. Cell migration in hRMEC was detected by cell scratch assay. The Seahorse XFe96 Cell Energy Metabolism analyzer measured extracellular acidification rate (ECAR) of intracellular glycolysis, glycolysis reserve, and glycolysis capacity. One-way analysis of variance was used to compare groups. ResultsIn vivo animal experiment: compared with normal group, the neovascularization increased in OIR group (t=41.621, P＜0.001). Compared with OIR group, the number of vascular endothelial nuclei breaking through ILM in OIR+SB431542 group was significantly reduced, and the difference was statistically significant (F=36.183, P＜0.001). MTT test results showed that compared with normal group and hypoxia+SB431542 group, the cell proliferation of hypoxia group and hypoxia+DMSO group was significantly increased, and the difference was statistically significant (F=39.316, P＜0.01). The cell proliferation of hypoxia+SB431542 group was significantly lower than that of hypoxia+DMSO group, and the difference was statistically significant (t=26.182, P＜0.001). The number of intact lumen formation and migration cells in normal group, hypoxia group, hypoxia+DMSO group and hypoxia+SB431542 group were statistically significant (F=34.513, 41.862; P＜0.001, ＜0.01). Compared with the hypoxia+DMSO group, the number of intact lumen formation and migrating cells in the hypoxia+SB431542 group decreased significantly, and the differences were statistically significant (t=44.723, 31.178; P＜0.001, ＜0.01). The results of cell energy metabolism showed that compared with the hypoxia +DMSO group, the ECAR of intracellular glycolysis and glycolysis reserve in the hypoxia +SB431542 group was decreased, and the ECAR of glycolysis capacity was increased, with statistical significance (t=26.175, 33.623, 37.276; P＜0.05). ConclusionSB431542 can inhibit the proliferation, migration and the ability to form lumens, reduce the level of glycolysis of hRMECs cells induced by hypoxia.
ObjectiveTo observe the effect of interleukin-8 (IL-8) on the adhesion and migration of retinal vascular endothelial cells (RCEC). MethodsA cell experiment. Human RCEC (hRCEC) was divided into normal control group (N group), advanced glycation end product (AGE) treatment group (AGE group), and AGE-induced combined IL-8 antagonist SB225002 treatment group (AGE+SB group). The effect of AGE on IL-8 expression in hRCEC was observed by Western blot. The effect of SB225002 on hRCEC migration was observed by cell scratch assay. The effects of SB225002 on leukocyte adhesion and reactive oxygen species (ROS) on hRCEC were detected by flow cytometry. Student-t test was performed between the two groups. One-way analysis of variance was performed among the three groups. ResultsCompared with group N, the expression level of IL-8 in cells of AGE group was significantly increased, with statistical significance (t=25.661, P＜0.001). Compared with N group and AGE+SB group, cell mobility in AGE group was significantly increased (F=29.776), leukocyte adhesion number was significantly increased (F=38.159, 38.556), ROS expression level was significantly increased (F=22.336), and the differences were statistically significant (P＜0.05). ConclusionIL-8 antagonist SB225002 may down-regulate hRCEC adhesion and migration by inhibiting ROS expression.
Coronary heart disease is a kind of heart disease that is caused by atherosclerosis.The lipid deposition in the vessel wall results in occlusion of coronary artery and stenosis, which could induce myocardial ischemia and oxygen deficiency. Intervention therapies like percutaneous coronary intervention (PCI) and coronary stent improve myocardial perfusion using catheter angioplasty to reduce stenosis and occlusion of coronary artery lumen. Accordingly, intervention therapies are widely applied in clinic to treat ischemic cardiovascular disease, arterial intima hyperplasia and other heart diseases, which could save the patients′ life rapidly and effectively. However, these interventions also damage the original endothelium, promote acute and subacute thrombosis and intimal hyperplasia, and thus induce in stent restenosis (ISR) eventually. Studies indicated that the rapid reendothelialization of damaged section determined postoperative effects. In this review, reendothelialization of implants after intervention therapy is discussed, including the resource of cells contributed on injured artery, the influences of implanted stents on hemodynamic, and the effects of damaged degree on reendothelialization.
Objective To observe the effects of overexpression of polypyrimidine tract binding protein-associated splicing factor (PSF) on the endoplasmic reticulum (ER) oxidative stress damage of human retinal microvascular endothelial cells (hRMEC) under high concentration of 4-hydroxynonenal (4-HNE). MethodsThe logarithmic growth phase hRMEC cultured in vitro was divided into normal group, simple 4-HNE treatment group (simple 4-HNE group), empty plasmid combined with 4-HNE treatment group (Vec+4-HNE group), and PSF high expression combined with 4-HNE treatment group (PSF+4-HNE group). In 4-HNE group, Vec+4-HNE group, and PSF+4-HNE group cell culture medium, 10 μmol/L 4-HNE was added and stimulated for 12 hours. Subsequently, the Vec+4-HNE group and PSF+4-HNE group were transfected with transfection reagent liposome 2000 into pcDNA empty bodies and pcDNA-PSF eukaryotic expression plasmids, respectively, for 24 hours. Flow cytometry was used to detect the effects of 4-HNE and PSF on cell apoptosis. The effect of PSF overexpression on the expression of reactive oxygen species (ROS) in hRMEC was detected by 2', 7'-dichlorodihydrofluorescein double Acetate probe. Western blot was used to detect ER oxide protein 1 (Ero-1), protein disulfide isomerase (PDI), C/EBP homologous transcription factor (CHOP), glucose regulatory protein (GRP) 78, protein kinase R-like ER kinase (PERK)/phosphorylated PERK (p-PERK), and Eukaryotic initiation factor (eIF) 2α/the relative expression levels of phosphorylated eIF (peIF) and activated transcription factor 4 (ATF4) proteins in hRMEC of normal group, 4-HNE group, Vec+4-HNE group, and PSF+4-HNE group. Single factor analysis of variance was performed for inter group comparison. ResultsThe apoptosis rates of the simple 4-HNE group, Vec+4-HNE group, and PSF+4-HNE group were (22.50±0.58)%, (26.93±0.55)%, and (11.70±0.17)%, respectively. The intracellular ROS expression levels were 0.23±0.03, 1.60±0.06, and 0.50±0.06, respectively. The difference in cell apoptosis rate among the three groups was statistically significant (F=24.531, P＜0.05). The expression level of ROS in the Vec+4-HNE group was significantly higher than that in the simple 4-HNE group and the PSF+4-HNE group, with a statistically significant difference (F=37.274, P＜0.05). The relative expression levels of ER Ero-1 and PDI proteins in the normal group, simple 4-HNE group, Vec+4-HNE group, and PSF+4-HNE group were 1.25±0.03, 0.45±0.03, 0.63±0.03, 1.13±0.09, and 1.00±0.10, 0.27±0.10, 0.31±0.05, and 0.80±0.06, respectively. The relative expression levels of CHOP and GRP78 proteins were 0.55±0.06, 1.13±0.09, 0.90±0.06, 0.48±0.04 and 0.48±0.04, 1.25±0.03, 1.03±0.09, 0.50±0.06, respectively. The relative expression levels of Ero-1 (F=43.164), PDI (F=36.643), CHOP (F=42.855), and GRP78 (F=45.275) proteins in four groups were compared, and the differences were statistically significant (P＜0.05). Four groups of cells ER p-pERK/pERK (F=35.755), peIF2 α/ The relative expression levels of eIF (F=38.643) and ATF4 (F=31.275) proteins were compared, and the differences were statistically significant (P＜0.05). ConclusionPSF can inhibit cell apoptosis and ROS production induced by high concentration of 4-HNE, and its mechanism is closely related to restoring the homeostasis of ER and down-regulating the activation level of PERK/eIF2α/ATF4 pathway.
Objective To investigate the effect and potential mechanism of bone marrow mesenchymal stem cells (BMSCs) - derived extracellular vesicles (EVs) on lung tissue injury in mice with severe acute pancreatitis (SAP). Methods A total of 24 specific pathogen free grade male C57BL/6 mice and primary mouse lung microvascular endothelial cells (PMVECs) were selected. The mice were divided into sham group, SAP group, and BMSC group, with 8 mice in each group. The mouse primary PMVECs were divided into model group [sodium taurocholate (NaTC) group], BMSC-EV group, and control group. Extraction and characterization of healthy mouse BMSCs and their derived extracellular vesicles (BMSC-EVs) were conducted. A mouse model of SAP was established, and BMSC-EVs were injected into SAP mice by tail vein or intervened in PMVECs in vitro, to observe the pathological damage of pancreatic and lung tissues, the changes of serum amylase, lipase, and inflammatory factors [tumor necrosis factor α (TNF-α), interleukin-6 (IL-6)], the expression of inflammatory factors of lung tissues and PMVECs, and the endothelial cell barrier related proteins [E-cadherin, ZO-1, intercellular cell adhesion molecule-1 (ICAM-1)], and tight junctions between PMVECs to explore the effects of BMSC-EVs on pancreatic and lung tissues in SAP mice and PMVECs in vitro. Results BMSCs had the potential for osteogenic, chondrogenic, and lipogenic differentiation, and the EVs derived from them had a typical cup-shaped structure with a diameter of 60-100 nm. BMSC-EVs expressed the extracellular vesicle-positive proteins TSG101 and CD63 and did not express the negative protein Calnexin. Compared with the mice in the sham group, the SAP mice underwent significant pathological damage to the pancreas (P<0.05), and their serum amylase, lipase, inflammatory factor IL-6, and TNF-α levels were significantly up-regulated (P<0.05); whereas, BMSC-EVs markedly ameliorated the pancreatic tissue damage in the SAP mice (P<0.05), down-regulated the levels of peripheral serum amylase, lipase, IL-6 and TNF-α (P<0.05), and up-regulated the level of anti-inflammatory factor IL-10 (P<0.05). In addition to this, the SAP mice showed significant lung histopathological damage (P<0.05), higher neutrophils and macrophages infiltration (P<0.05), higher levels of the inflammatory factors TGF-β and IL-6 (P<0.05), as well as reduced barrier protein E-cadherin, ZO-1 expression and elevated expression of ICAM-1 (P<0.05). BMSC-EVs significantly ameliorated lung histopathological injury, inflammatory cells infiltration, inflammatory factor levels, and expression of barrier proteins, and suppressed ICAM-1 expression (P<0.05). In the in vitro PMVECs experiments, it was found that intercellular tight junctions were broken in the NaTC group, and the levels of inflammatory factors TNF-α and IL-6 were significantly up-regulated (P<0.05), the protein expression of E-cadherin and ZO-1 was significantly down-regulated (P<0.05), and the expression of ICAM-1 was significantly up-regulated (P<0.05). BMSC-EVs significantly improved intercellular tight junctions in the NaTC group and inhibited the secretion of TNF-α and IL-6 (P<0.05), up-regulated the expression of the barrier proteins E-cadherin and ZO-1, and down-regulated the expression of ICAM-1 (P<0.05). Conclusion BMSC-derived EVs ameliorate lung tissue injury in SAP mice by restoring the lung endothelial cell barrier and inhibiting inflammatory cell infiltration.
ObjectiveTo observe the effects of p21 activated kinase 4 (PAK4) on the mitochondrial function and biological behavior in retinal vascular endothelial cells. MethodsThe experimental study was divided into two parts: in vivo animal experiment and in vitro cell experiment. In vivo animal experiments: 12 healthy C57BL/6J male mice were randomly divided into normal control group and diabetes group, with 6 mice in each group. Diabetes mice were induced by streptozotocin to establish diabetes model. Eight weeks after modeling, quantitative real-time polymerase chain reaction and Western blots were performed to detect the expression of PAK4 in diabetic retinas. In vitro cell experiments: the human retinal microvascular endothelial cells (hRMEC) were divided into three groups: conventional cultured cells group (N group), empty vector transfected (Vector group); pcDNA-PAK4 eukaryotic expression plasmid transfected group (PAK4 group). WB and qPCR were used to detect transfection efficiency, while scratching assay, cell scratch test was used to detect cell migration in hRMEC of each group. In vitro white blood cell adhesion experiment combined with 4 ', 6-diamino-2-phenylindole staining was used to detect the number of white blood cells adhering to hRMEC in each group. The Seahorse XFe96 cell energy metabolism analyzer measures intracellular mitochondrial basal respiration, adenosine triphosphate (ATP) production, maximum respiration, and reserve respiration capacity. The t-test was used for comparison between the two groups. Single factor analysis of variance was used for comparison among the three groups. ResultsIn vivo animal experiments: compared with normal control group, the relative expression levels of PAK4 mRNA and protein in retina of diabetic mice were significantly increased, with statistical significance (t=25.372, 22.419, 25.372; P＜0.05). In vitro cell experiment: compared with the N group and Vector group, the PAK4 protein, mRNA relative expression and cell mobility in the hRMEC of PAK4 group were significantly increased, with statistical significance (F=36.821, 38.692, 29.421; P＜0.05). Flow cytometry showed that the adhesion number of leukocytes on hRMEC in PAK4 group was significantly increased, and the difference was statistically significant (F=39.649, P＜0.01). Mitochondrial pressure measurement results showed that the capacity of mitochondrial basic respiration, ATP production, maximum respiration and reserve respiration in hRMEC in PAK4 group was significantly decreased, with statistical significance (F=27.472, 22.315, 31.147, 27.472; P＜0.05). ConclusionOver-expression of PAK4 impairs mitochondrial function and significantly promotes leukocyte adhesion and migration in retinal vascular endothelial cells.
