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.
ObjectiveTo prepare polyurethane (PU) microspheres and evaluate its physicochemical properties and biocompatibility for biomedical applications in vitro.
MethodsThe PU microspheres were prepared by self-emulsification procedure at the emulsification rates of 1 000, 2 000, 3 000, and 4 000 r/min. The molecular structure was tested by Fourier transform infrared spectrometer and the surface and interior morphology of PU microspheres were observed by scanning electron microscopy (SEM). PU microspheres prepared at best emulsification rate were selected for the subsequent experiment. The human umbilical vein endothelial cells (HUVECs) were cultured and seeded on the materials, then cell morphology and adhesion status were observed by calcein-acetoxymethylester/pyridine iodide (Calcein-AM/PI) staining. The cells were cultured in the H-DMEM containing 10%FBS with additional 1% phenol (group A), in the extracts of PU prepared according to GB/T 16886.12 standard (group B), and in H-DMEM containing 10%FBS (group C), respectively. Cell counting kit 8 (CCK-8) assay was used to detect the cell viability. The blood compatibility experiments were used to evaluate the blood compatibility, the PU extracts as experimental group, stroke-physiological saline solution as negative control group, and distilled water as positive control group. The hemolytic rate was calculated.
ResultsThe SEM results of PU microspheres at the emulsification rate of 2 000 r/min showed better morphology and size. The microstructure of the PU was rough on the surface and porous inside. The Calcein-AM/PI staining showed that the HUVECs attached to the PU tightly and nearly all cells were stained by green. CCK-8 assays demonstrated that group B and group C presented a significantly higher cell proliferative activity than group A (P<0.05), indicating low cytotoxicity of the PU. The absorbance value was 0.864±0.002 in positive control group and was 0.015±0.001 in negative control group. The hemolysis rate of the PU extracts was 0.39%±0.07% (<5%), indicating no hemolysis.
ConclusionThe PU microspheres are successfully prepared by self-emulsification. The scaffold can obviously promote cell attachments and proliferation and shows low cytotoxicity and favorable blood compatibility, so it might be an ideal filler for soft tissue.
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.
Objective To explore the effect of natural hirudin on proliferation of human microvascular endothelial cells (HMVECs) and its preliminary mechanism of promoting angiogenesis. Methods Three-dimensional culture models of HMVECs were established in vitro and observed by inverted phase contrast microscopy after 24 hours of culturing. Then, the three-dimensional culture models of HMVECs were treated with different concentrations (1, 4, and 7 ATU/mL) of the natural hirudin, respectively, and Dulbecco’s modified Eagle’s medium containing 10% fetal bovine serum as control. The cell proliferations of 4 groups were detected by cell counting kit 8 (CCK-8) method at 24, 48, and 72 hours; the angiogenesis of 4 groups were observed by tube formation assay at 24 hours; the expressions of vascular endothelial growth factor (VEGF) and Notch1 of HMVECs in 4 groups were observed by immunofluorescence staining at 24 hours. Results The observation of cells in three-dimensional culture models showed that HMVECs attached to Matrigel well, and the cells formed tube structure completely after 24 hours. The results of CCK-8 test showed that the absorbance (A) value of 1 and 4 ATU/mL groups were higher than that of control group at each time point (P<0.05), andA value of 4 ATU/mL group was the highest. The A value of 7 ATU/mL group was significantly lower than those of 1 and 4 ATU/mL groups and control group (P<0.05). The tube formation assay showed that the tube structure was more in 1 and 4 ATU/mL groups than in 7 ATU/mL group and control group, and in 4 ATU/mL group than in 1 ATU/mL group, showing significant differences (P<0.05). There was no significant difference between 7 ATU/mL group and control group (P>0.05). The results of immunofluorescence staining showed that compared with control group, the Notch1 expression was higher in 1 and 4 ATU/mL groups and lower in 7 ATU/mL group; and there was significant difference between 4 and 7 ATU/mL groups and control group (P<0.05). The VEGF expression was higher in 1, 4, and 7 ATU/mL groups than in control group, in 4 ATU/mL group than in 1 and 7 ATU/mL groups, showing significant differences (P<0.05). Conclusion Natural hirudin can promote angiogenesis at low and medium concentrations, but suppress angiogenesis at high concentrations. Its mechanism may be related to the VEGF-Notch signal pathway.
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.
ObjectiveTo compare the different effects of ubiquitin(UB) on human umbilical vein endothelial cells (HUVECs) and macrophages under normal circumstances,and analyze whether UB could protect HUVECs from lipopolysaccharide(LPS) induced injury.
MethodsThe morphologic changes of HUVECs in vitro with up-rising concentrations of UB interventions were observed. HUVECs and human macrophages in vitro were divided into 4 groups according to UB concentration (0.01 μg/mL,0.1 μg/mL, 1 μg/mL, and 10 μg/mL). Supernatant and cells of each group were collected in 24 h after UB intervention. The levels of TNF-α and VCAM-1 in supernatant were measured by ELISA while NF-κB protein level in cells was detected by Western blot. HUVECs were divided into a LPS group(LPS 10 μg/mL) and an UB+LPS group(UB 0.1 μg/mL,LPS 10 μg/mL). The supernatant of the two groups were collected in 8,16 and 24 h after LPS and UB intervention. The levels of TNF-α and VCAM-1 in supernatant were measured by ELISA.
ResultsThe injury of HUVECs got worse with the ascending concentrations of UB.At the concentration of 50 μg/mL,UB induced HUVECs got ballooned and died massively. With the increase of UB concentration,the levels of TNF-α and VCAM-1 in HUVECs' supernatant ascended firstly and then descended,while those in human macrophages' supernatant ascended gradually. zHowever,the tendency of the NF-κB protein level in the two kinds of cells was similar when the concentration of UB increased.At the consentration of 0.1 μg/mL or 1 μg/mL,ubiquitin induced NF-κB protein level obviously increased.At the concentration of 0.01 μg/mL or 10 μg/mL,UB induced the protein level was similar with those of the control group and even decreased slightly. There was no significant difference in TNF-α or VCAM-1 levels at each time point between the LPS group and the UB+LPS group.
ConclusionsUB injuries HUVECs obviously at a low concentration but injuires human macrophages at much higher concentraton. UB can not protect HUVECs from LPS-induced injury in vitro.
Objective
To investigate the effects of vascular endothelial growth factor C (VEGF-C) gene modified lymph nodes on promoting proliferation of lymphatic endothelial cells in the surrounding tissues.
Methods
Thirty-six Sprague Dawley rats, weighing 200.1-271.5 g, were randomly divided into 2 groups (n=18). After the in situ axillary lymph nodes transplantation models were established in both groups, 1.5 × 108 PFU Ad-VEGF-C-Flag and Ad-Flag were injected into the transplanted lymph nodes in experimental group and control group, respectively. At 3 days after injection, the axillary lymph nodes were harvested to observe the expression of Flag; at 1, 2, and 4 weeks after injection, the axillary lymph nodes and the surrounding tissues were harvested to observe the expression of Prxo-1 protein and to calculate the fluorescence density; at 2 and 4 weeks after injection, the absorbance (A) value of treated blood at 620 nm was calculated to observe lymphatic back-flow function improvement; the rats without treatment served as normal control group, and the rats with in situ axillary lymph nodes transplantation model served as blank control group.
Results
At 3 days after injection, the expression of Flag could be detected in experimental group and control group. The fluorescence density of Prox-1 protein in experimental group increased at 1, 2, and 4 weeks, and it was significantly higher than that in control group (P lt; 0.05). The A values of normal control group and blank control group were 0.539 ± 0.020 and 0.151 ± 0.007, respectively. The A values of experimental group and control group were 0.170 ± 0.011 and 0.168 ± 0.010 at 2 weeks, and 0.212 ± 0.016 and 0.197 ± 0.006 at 4 weeks, which were significantly lower than those of normal control group (P lt; 0.05), but no significant difference was found when compared with blank control group, and between the experimental group and control group (P gt; 0.05).
Conclusion
The VEGF-C gene modified lymph nodes can stimulate the proliferation of lymphatic endothelial cells in the surrounding tissues. However, it has no improved effect on lymphatic back-flow function in the affected limb.
Objective To observe the effect of Nodal on the biological behavior of retinal vascular endothelial cells (RF/6A cells) in monkeys with high glucose. MethodsRF/6A cells were divided into normal group, mannitol group, high glucose group, high glucose combined with non-specific small interfering RNA treatment group (HG+NC group), high glucose combined with small interfering Nodal treatment group (HG+siNodal group). The transfection efficiency of siNodal was observed by real-time fluorescence quantitative PCR and western blot protein immunoblotting. The effect of Nodal on the proliferation of RF/6A cells was detected by thiazole blue colorimetry. The effect of Nodal on migration ability of RF/6A cells was detected by cell scratch assay. The effect of Nodal on the formation of RF/6A cell lumen was measured by Matrigel three-dimensional in vitro. The expression of extracellular signal phosphorylated regulated kinase 1/2 (pERK1/2) in RF/6A cells was detected by western blot protein immunoblotting. One-way analysis of variance was used to compare groups. ResultsCompared with HG+NC group, Nodal protein (F=33.469) and mRNA relative expression levels (F=38.191) in HG+siNodal group were significantly decreased, cell proliferation was significantly decreased (F=28.548), and cell migration ability was significantly decreased (F=24.182). The number of cell lumen formation was significantly decreased (F=52.643), and the differences were statistically significant (P＜0.05). Compared with HG+NC group, the relative expression of pERK1/2 protein in HG+siNodal group was significantly decreased, and the difference was statistically significant (F=44.462, P＜0.01). ConclusionsSilencing Nodal expression can inhibit proliferation, migration and tube formation of RF/6A cells induced by high glucose. It may act by inhibiting pERK1/2 expression.
Objective To investigate the relationships between circulating tumor cells (CTCs), circulating tumor endothelial cells (CTECs) and treatment methods in patients with nasopharyngeal carcinoma (NPC) at different stages of treatment. Methods The data of NPC patients at different treatment periods in West China Hospital of Sichuan University from March 2016 to November 2019 were retrospectively collected. The patients received CTCs test and part of those patients received CTECs test, by subtraction enrichment-immunostaining-fluorescence in situ hybridization. The relationships of CTCs and CTECs with radiotherapy and chemotherapy, and the correlations between CTCs and CTECs in NPC patients were analyzed. Results A total of 191 patients were included. Among them, there were 66 cases before initial treatment, 38 cases after induction chemotherapy, and 87 cases after concurrent chemoradiotherapy. A total of 127 patients received CTECs test, including 41 cases before initial treatment, 29 cases after induction chemotherapy, and 57 cases after concurrent chemoradiotherapy. The positive rates of CTCs were 89.4%, 81.6% and 69.0% respectively in the three stages of treatment, and the difference was statistically significant only between the pre-treatment group and the post-concurrent chemoradiotherapy group (P=0.003). The number of CTCs in the post-concurrent chemoradiotherapy group was lower than that in the pre-treatment group and the post-induction chemotherapy group (P<0.001, P=0.002). The number of triploid CTCs in the post-concurrent chemoradiotherapy group was significantly different from that in the pre-treatment group and the post-induction chemotherapy group (P=0.009, P=0.013). The number of tetraploid CTCs in the post-concurrent chemoradiotherapy group was significantly different from that in the post-induction chemotherapy group (P=0.007). The number of polyploidy (pentaploid or > 5 copies of chromosome 8) CTCs in the post-concurrent chemoradiotherapy group was significantly different from that in the pre-treatment group (P<0.001). The positive rates of CTECs were 70.7%, 82.8% and 64.9% respectively in the three stages of treatment, and the difference was not statistically significant (P>0.05). The number of CTECs in the post-concurrent chemoradiotherapy group was only lower than that in the post-induction chemotherapy group (P=0.009). There was no significant difference in the number of triploid or tetraploid CTECs among the three groups (P=0.265, P=0.088). The number of polyploid CTECs was statistically different only between the post-concurrent chemoradiotherapy group and the post-induction chemotherapy group (P=0.007). Spearman correlation analysis showed that there was a significant positive correlation between CTCs and CTECs (rs=0.437, P<0.001). Conclusions Concurrent chemoradiotherapy plays a decisive role in reducing the number of CTCs in the blood of NPC patients, while induction chemotherapy does not appear to directly cause changes in the number of CTCs. In NPC patients, different types of CTCs have different responses to different treatments. There is a significant positive correlation between CTECs level and CTCs level in NPC.
Objective To observe the effect of high expression of polypyrimidine tract-binding protein-associated splicing factor (PSF) on low concentration of 4-hydroxynonenal (4-HNE) induced human retinal microvascular endothelial cells (HRMECs), and explore the possible mechanism. MethodsThe HRMECs cultured in vitro were divided into 4-HNE treated group, PSF overexpression group combined with 4-HNE group (PSF+4-HNE group), PSF overexpression+ML385 treatment combined with 4-HNE group (PSF+ML385+4-HNE group), and 4-HNE induced PSF overexpression group with LY294002 pretreatment (LY294002+4-HNE+PSF group). Cell culture medium containing 10 μmmol/L 4-HNE was added into 4-HNE treatment group, PSF+4-HNE group, PSF+ML385+4-HNE group for 12 hours to stimulate oxidative stress. 1.0 μg of pcDNA-PSF eukaryotic expression plasmid were transfected into PSF+4-HNE group and PSF+ML385+4-HNE group to achieve the overexpression of PSF. Also cells were pretreated with ML385 (5 μmol/L) for 48 hours in the PSF+ML385+4-HNE group, meanwhile within the LY294002+4-HNE+PSF group, after pretreatment with LY294002, cells were treated with plasmid transfection and 4-HNE induction. Transwell detects the migration ability of PSF to HRMECs. The effect of PSF on the lumen formation of HRMECs was detected by using Matrigel in vitro three-dimensional molding method. Flow cytometer was used to detect the effect of PSF overexpression on reactive oxygen (ROS) level in HRMECs. Protein immunoblotting was used to detect the relative expression of PSF, nuclear factor E2 related factor 2 (Nrf2), heme oxygenase-1 (HO-1) protein, and phosphoserine threonine protein kinase (pAkt) protein. The comparison between the two groups was performed using a t-test. ResultsThe number of live cells, migrating cells, and intact lumen formation in the 4-HNE treatment group and the PSF+4-HNE group were 1.70±0.06, 0.80±0.13, 24.00±0.58, 10.00±0.67, and 725.00±5.77, 318.7±12.13, respectively. There were significant differences in the number of live cells, migrating cells, and intact lumen formation between the two groups (t=12.311, 15.643, 17.346; P＜0.001). The results of flow cytometry showed that the ROS levels in the 4-HNE treatment group, PSF+4-HNE group, and PSF+ML385+4-HNE group were 816.70±16.67, 416.70±15.44, and 783.30±17.41, respectively. There were statistically significant differences between the two groups (t=16.311, 14.833, 18.442; P＜0.001). Western blot analysis showed that the relative expression levels of pAkt, Nrf2, and HO-1 proteins in HRMECs in the 4-HNE treatment group, PSF+4-HNE group and LY294002+4-HNE+PSF group were 0.08±0.01, 0.57±0.04, 0.35±0.09, 0.17±0.03, 1.10±0.06, 0.08±0.11 and 0.80±0.14, 2.50±0.07, 0.50±0.05, respectively. Compared with the PSF+4-HNE group, the relative expression of pAkt, Nrf2, and HO-1proteins in the LY294002+4-HNE+PSF group decreased significantly, with significant differences (t=17.342, 16.813, 18.794; P＜0.001). ConclusionPSF upregulates the expression of HO-1 by activating the phosphatidylinositol 3 kinase/Akt pathway and inhibits cell proliferation, migration, and lumen formation induced by low concentrations of 4-HNE.
