ObjectiveTo elucidate whether hypoxia induced factor-1α (HIF-1α) gene improved hypoxia tolerant capability of bone marrow mesenchymal stem cells uptake(MSCs) or not and whether the capability was related to glucose uptake increase in hypoxia MSCs ex vivo or not. MethodsMSCs were randomly divided into normoxia non-HIF-1α transfection group (control group), normoxia HIF-1α transfection group, hypoxia non-HIF-1α transfection group, and hypoxia HIF-1α transfection group and then each group was cultured with normoxia (5% CO2 at 37 ℃) or hypoxia (94% N2, 1% O2, 5% CO2 at 37 ℃) for 8 h, respectively. Finally, the expressions of HIF-1α were detected by immunocytochemistry, RT-PCR, and Western blot methods, respectively. Apoptosis ratio (AR) and death ratio (DR) were tested by flow cytometry. The proliferation was detected by MTT method. Glucose uptake was assayed by radiation isotope method. Results① Compared with the normoxia non-HIF-1α transfection group, the expression of HIF-1α mRNA significantly increased (Plt;0.01) in the normoxia HIF-1α transfection group except for its protein (P=0.187); Both of mRNA and protein expressions of HIF-1α in the hypoxia HIF-1α transfection group were significantly higher than those in the hypoxia non-HIF-1α transfection group (Plt;0.01). ② The AR (P=0.001) and DR (P=0.003) in the hypoxia HIF-1α transfection group were significantly lower thanthose in the hypoxia non-HIF-1α transfection group, both of which were significantly higher than those in the normoxia non-HIF-1α transfection group (Plt;0.01). ③ The proliferation of MSCs in the hypoxia HIF-1α transfection group was significantly higher than that in the hypoxia non-HIF-1α transfection group (P=0.004), which significantly lower than that in the normoxia non-HIF-1α transfection group (P=0.001). ④ Compared with the hypoxia non-HIF-1α transfection group, the 3H-G uptake capability (P=0.004) of MSCs significantly increased in the hypoxia HIF-1α transfection group, which was significantly lower than that in the normoxia non-HIF-1α transfection group (P=0.001). ⑤ There were significantly negative relation between AR and HIF-1α protein (r=－0.71，P=0.005) or 3H-G uptake (r=－0.65，P=0.004), and significantly positive relation between HIF-1α protein expression and 3H-G uptake (r=0.77, P=0.003). ConclusionHIF-1α gene significantly improves anti-hypoxia capability of MSCs, which is fulfilled by increasing glucose upake.
Hypoxia inducible factor-1 (HIF-1) is the main transcription factor and the core regulator for cells to adapt to hypoxia, and oxygen homeostasis is achieved by controlling and utilizing oxygen delivery. Autophagy and apoptosis play an important role in determining cell fate and maintaining cell homeostasis. In recent years, it has been found that the dynamic change of HIF-1 expression plays a key role in the hypoxic adaptive response of cardiomyocytes. The regulation of HIF-1 on autophagy and apoptosis of hypoxic cardiomyocytes determines the survival of cardiomyocytes, which is of great significance for the prognosis of ischemic heart disease.
ObjectiveUnder hypoxic conditions, the survival and apoptosis of human amniotic mesenchymal stem cells (hAMSCs) were observed by transient transfection of hypoxia-inducible factor 1α (HIF-1α) gene, to investigate the effect of HIF-1α on hypoxic tolerance of hAMSCs.MethodsThe hAMSCs were isolated and cultured from amniotic membrane tissue from voluntary donors who were treated with cesarean section. And the morphological observation by inverted phase contrast microscope and immunofluorescence detection of the expressions of stem cell markers OCT-4 and NANOG were performed to identify the cultured cells. The third generation hAMSCs were treated with 200 μmol/L CoCl2, and transient transfection of plasmids were added according to the following grouping: group A was hAMSCs blank group; group B was pcDNA3.1 negative control group; group C was short hairpin RNA (shRNA) negative control group; group D was shRNA-HIF-1α interference group; group E was pcDNA3.1-HIF-1α over expression group. Cell survival rate of each group was measured by cell counting kit 8 (CCK-8) at 12, 24, 48 hours after hypoxia treatment. Flow cytometry was used to detect apoptosis rate of each group at 24 hours after hypoxia treatment. The expression levels of HIF-1α, vascular endothelial growth factor (VEGF), B-cell lymphoma 2 (Bcl-2), Bax, and cleaved Caspase-3 (C-Caspase-3) proteins were detected by Western blot at 24 hours after hypoxia treatment.ResultsCCK-8 assay showed that the cell survival rate of group D was significantly lower than those of groups A and C at all time points after hypoxia treatment; while the cell survival rate in group E was significantly increased than those in groups A and B, and the diffrences at 24 hours were significant (P<0.05). In group E, the cell survival rate at 24 hours was significantly higher than those at 12 and 48 hours (P<0.05). The results of flow cytometry showed that the apoptosis rate in group D was significantly higher than those in groups A and C (P<0.05), and the apoptosis rate in group E was significantly lower than those in groups A and B (P<0.05). Western blot showed that the expressions of HIF-1α, VEGF, and Bcl-2 proteins in group D were significantly decreased when compared with those in groups A and C, and the expressions of Bax and C-Caspase-3 proteins were significantly increased (P<0.05). On the contrary, the expressions of HIF-1α, VEGF, and Bcl-2 proteins in group E were significantly higher than those in groups A and B, and the expressions of Bax and C-Caspase-3 proteins were significantly decreased (P<0.05).ConclusionOverexpression of HIF-1α gene can significantly improve hAMSCs tolerance to hypoxia, the mechanism may be related to up-regulation of VEGF and Bcl-2 expressions, and down-regulation of Bax and C-Caspase-3 expressions.
Objective To investigate the expression of hypoxia inducible factor 1(HIF1alpha;) in ratsprime; retinae during the embryonic and earlier postnatal period. Methods The retinal expression patterns of HIF-1alpha; protein and mRNA of embryonic day 12 (E12), E16, E20, and postnatal day 1(P1) and P5 rats were determined by immunohistochemical staining and reverse transcriptionpolymerase chain reaction (RT-PCR). Results HIF-1alpha; protein was detected in the neural epithelial layer and the pigment epithelial layer at all those 5 timepoints, with higher expression in the ganglion cell layer and the inner plexiform layer, and seems limited to the ganglion cell layer when re tina became more mature. Embryonic rat retina had higher expression of HIF-1alpha; protein and mRNA than postnatal retina, the difference was significant (P＜0.01）. Conclusion The expression of HIF1alpha; in ratsprime;retina e differs from embryonic to earlier postnatal stages.
ObjectiveTo investigate the effect of emodin on the expression of hypoxia inducible factor (HIF)-1α protein in rats with severe acute pancreatitis-associated renal injury and explore the possible mechanisms. MethodsA total of 72 rats were randomly divided into sham-operated group (n=24), severe acute pancreatitis with renal injury group (injury group, n=24), and treatment group (n=24). The sham-operated and injury groups were given 1.5 mL saline through intragastric administration before operation while the treatment group was fed with the same amount of 50 mg/kg emodin diluent. The pancreas and pancreatic tail-segment was dissociated and the head of pancreas was occluded in rats to form the model, and blood vessel forceps were loosed after three hours. All the rats were sacrificed 12, 24 and 36 hours after modeling. The level of ascites, serum amylase, creatinine, blood urea nitrogen were detected. Hematoxylin-eosin staining was used to observe the pancreatic and renal pathological changes, and immunohistochemical method was used to detect the expression of HIF-1α protein level in the kidney. ResultsCompared with the sham-operated group, the level of ascites, serum amylase, creatinine, blood urea nitrogen and the expression of HIF-1α protein level increased significantly. The tissue damage of pancreas and the kidney became more serious. Compared with the injury group, the kidney and pancreas function of the treatment group had a better performance. HIF-1α protein level significantly increased in the treatment group, and the difference had a statistical significance (P<0.05). ConclusionEmodin has a good protective effect on severe acute pancreatitis-associated renal injury. It may function through up-regulation expression of HIF-1α protein level to improve the ability of the kidney to tolerate hypoxia, and then reduce the cell apoptosis and necrosis of the kidney.
To review the role of hypoxia inducible factor 1α (HIF-1α) in hypoxic-ischemic injury and its repair, and to analyze the possible mechanisms. Methods Recent l iterature on HIF-1α and its role in hypoxic-ischemic injury was reviewed and analyzed. Results HIF-1α was involved in the hypoxic-ischemic injury of various organs or tissues and their repair processes. Conclusion HIF-1α has a potential to treat common cl inical hypoxic-ischemic injuries and has a promisingfuture for appl ication.
ObjectiveTo explore the involvement of miR-126 and the role of mammalian target of rapamycin (mTOR)/hypoxia-induced factor 1 α (HIF-1 α) pathway in regulating human umbilical cord mesenchymal stem cells (hUCMSCs) exosomes (Exo) on vascular endothelial growth factor (VEGF)-A levels in high glucose-induced human retinal vascular endothelial cells (HRECs). MethodsThe hREC was cultured in EGM-2-MV endothelial cell culture medium with 30 mmol/L glucose and placed in hypoxic cell incubator by 1% oxygen concentration. The cell model of high glucose and low oxygen was established. After modeling, divided HRECs into Exo group, phosphate buffer saline (PBS) group, PBS+anti-miR126 group, Exo+anti-miR126 group, PBS+anti-mTOR group, and PBS+anti-HIF-1 α group. High-glucose and hypoxia-induced hREC in the PBS and Exo groups were respectively co-cultured with PBS and 100 μg/ml hUCMSC Exo. PBS+anti-mTOR group, PBS+anti-HIF-1 α group: 500 nmol/L mTOR inhibitor ADZ2014, 25 μmol/L HIF-1 α inhibitor YC-1 pretreatment for hREC 12 h, and then co-culture with PBS after High-glucose and hypoxia-induced. PBS+anti-miR126 group, Exo+anti-miR126 group: miR-126 LNA power inhibitor probe was transfected with high glucose, and co-cultured with PBS and hUCMSC Exo 6 h after transfection. Real-time polymerase chain reaction (qPCR) measured miRNA-126 expression levels in PBS, and Exo groups for 0, 8, 16 and 24 h. After 24 hof co-culture, the levels of mTOR and HIF-1 α in the cells of PBS and Exo groups were detected by immunofluorescence, Western blot and qPCR, respectively. Western blot, qPCR detection of VEGF-A expression levels in cells of the PBS+anti-mTOR and PBS+anti-HIF-1 α groups. The expression of VE GF-A, mTOR, and HIF-1 α mRNA was measured in cells of PBS+anti-miR126 group and Exo+anti-miR126 group by qPCR. Comparison between two groups was performed by t-test; one-way ANOVA was used for comparison between multiple groups. ResultsAt 0, 8, 16 and 24 h, the relative mRNA expression of miR-126 gradually increased in the Exo group (F=95.900, P＜0.05). Compared with the PBS group, The mTOR, HIF-1 α protein (t=3.466, 6.804), mRNA in HRECs in the Exo group, VEGF-A mRNA expression (t=8.642, 7.897, 6.099) were all downregulated, the difference was statistically significant (P＜0.05). The relative expression level of VEGF-Aprotein (t=3.337, 7.380) and mRNA (t=8.515, 10.400) was decreased in HRECs of the anti-mTOR+PBS group and anti-HIF-1 α+PBS group, differences were statistically significant (P＜0.05). The relative expression of VEGF-A, mTOR, and HIF-1 α mRNA was significantly increased in the cells of the Exo+anti-miR126 group, the differences were all statistically significant (t=4.664, 6.136, 6.247; P＜0.05). ConclusionsmiR-126 plays a role in regulating the effect of hUCMSCs exosomes on VEGF-A levels in high glucose-induced HRECs via mTOR-HIF-1 α pathway.
ObjectiveTo systematically review the correlation between the expression of hypoxia inducible factor-1α (HIF-1α) protein and different clinical pathological features of renal cell cancer. MethodsWe electronically searched databases including The Cochrane Library, PubMed, EMbase, CNKI, VIP, CBM and WanFang Data from inception to June 2015 to collect case-control studies investigating the correlation between HIF-1α protein expression and different clinical pathological features of renal cell cancer. Two reviewers independently screened literature, extracted data, and assessed the risk of bias of included studies. Then meta-analysis was performed using RevMan 5.3 software. ResultsA total of 8 case-control studies involving 429 cases of renal cell cancer and 130 cases of normal renal tissue were included. The results of meta-analysis showed that:HIF-1α protein expression was higher in the renal cell cancer group than that in the normal renal tissue group (OR=16.76, 95%CI 8.53 to 32.92, P<0.000 01); HIF-1α protein expression was higher in the lymph node metastasis group than that in the non-lymphnode metastasis group (OR=4.33, 95%CI 2.53 to 7.39, P<0.000 01); HIF-1α protein expression was higher in the TNM Ⅲ-IV group than that in the TNM I-Ⅱ group (OR=0.30, 95%CI 0.18 to 0.51, P<0.000 1); HIF-1α protein expression was higher in the Fuhrman pathology classification G3+G4 group than that in the G1+G2 group (OR=0.54, 95%CI 0.29 to 0.98, P=0.04). However, there were no significant differences in HIF-1α protein expression between the age≥50 group and the age <50 group (OR=1.09, 95%CI 0.54 to 2.19, P=0.82), and between the male group and the female group (OR=0.77, 95%CI 0.48 to 1.25, P=0.29). ConclusionHIF-1α protein expression is significantly correlated to the clinical stage and pathological grading of renal cell cancer. It is possibly involved in the initiation and development of renal cell cancer. Due to the limited quantity and quality of included studies, the above conclusion needs to be further verified by more high quality studies.
目的 通过复制人肝癌细胞株HepG2裸鼠皮下移植瘤模型，观察绿茶提取物表没食子儿茶素没食子酸酯（EGCG）干预对HepG2移植瘤新生血管生成的影响。 方法 瘤体接种复制HepG2移植瘤模型，荷瘤裸鼠20只随机分组，实验组给予EGCG溶液每日20 mg/（kg·只），腹腔注射3周，对照组给予等量灭菌注射用水3周，末次用药24 h，后处死裸鼠，剥离移植瘤。常规病理切片观察移植瘤组织结构；逆转录-聚合酶链式反应和免疫组织化学法检测移植瘤缺氧诱导因子-1α（HIF-1α）、血管内皮生长因子（VEGF）mRNA及蛋白表达，并通过检测CD34表达计数瘤组织微血管密度（MVD）。 结果 组织病理学观察实验组移植瘤见大量坏死区，瘤体内血管数量明显少于对照组；实验组HIF-1α、VEGF mRNA及蛋白表达水平比对照组均明显下调（P＜0.05），实验组MVD比对照组明显下降（P＜0.05）。 结论 EGCG可抑制荷瘤裸鼠HepG2移植瘤新生血管生成。
Objective To explore the change tendency of hypoxia-inducible factor-1α (HIF-1α) and extracellular signal-regulated kinase 1/2 (ERK1/2) in fetal rat cerebral cortex neurons cultured in vitro after hypoxia-ischemia reperfusion andto investigate their mutual relationship. Methods Cortical neurons obtained from cerebral cortex of 15 pregnant SD rats at16-18 days of gestation underwent primary culture. The primary neurons 5 days after culture were adopted to establ ish model of oxygen and glucose deprivation (OGD). The experiment was divided into 4 groups: the experimental group 1, culture medium was changed to neuron complete medium containing glucose after the preparation of OGD model to form reperfusion, and the neurons were observed 0, 2, 4, 8, 12 and 24 hours after reperfusion; the control group 1, the neurons were treated with normal medium; the experimental group 2, the neurons were pretreated with U0126 followed by the preparation of OGD model, and the neurons were observed 4 and 8 hours after reperfusion; the control group 2, the neurons were pretreated with DMSO, and other treatments were the same as the experimental group 2. Expressions of HIF-1α, VEGF protein, ERK1/2 and p-ERK1/2 were detected by Western blot. Expression and distribution of p-ERK1/2 and HIF-1α protein were detected by SABC immunocytochemistry method. Results Compl icated synaptic connections between cortical neurons processes were observed 5 days after culture. The expression of HIF-1α and VEGF were increased gradually, peaked at 8 hours, and decreased gradually after 12 hours in the experimental group 1, and there were significant differences between the experimental group 1 and the control group 1 (P lt; 0.05). There was no significant difference between the experimental group 1 and the control group 1 in terms of ERK1/2 protein expression (P gt; 0.05). The p-ERK1/2 protein expression in the experimental group 1 started to increase at 2 hours peaked at 4 hours, and started to decrease at 8 hours, showing significant differences compared with the control group 1 (P lt; 0.01). In the experimental group 2, the p-ERK1/2 protein decreased, and HIF-1αand VEGF protein expression subsequentlydecreased, showing significant differences compared with the control group 2 (P lt; 0.05). There was no significant difference between the experimental group 2 and the control group 2 in terms of ERK1/2 protein expression at each time point (P gt; 0.05). Immunocytochemistry staining showed that p-ERK1/2 and HIF-1α expression decreased, and the yellow-brown staining of the neurons was reduced. Conclusion Expressions of HIF-1α and its target-gene VEGF protein in the cortex neurons after OGD reperfusion are time-dependent. Their expressions decrease when ERK1/2 signal ing pathway is inhibited, indicating the pathway plays an important role in the regulation of HIF-1α and VEGF induced by OGD of cortical neurons