Effect of Gualou Xiebai Banxiatang on Myocardial Microangiogenesis and HIF-1α/VEGF-related Pathways in Myocardial Ischemia Model Rats / 中国实验方剂学杂志

ObjectiveTo investigate the effect of Gualou Xiebai Banxiatang on cardiac function and myocardial histopathological changes in rats with ischemic myocardial injury， and to observe the effect of myocardial microvascular density （MVD）， phosphatidylinositol 3-kinase （PI3K）， mammalian target of rapamycin （mTOR）， hypoxia-inducible factor-1 alpha （HIF-1α）， and vascular endothelial growth factor （VEGF） signaling pathways on myocardial microangiogenesis. MethodSeventy male SD rats were randomly selected， with six rats in the normal group. The remaining rats were fed a high-fat diet and injected with isoproterenol hydrochloride （ISO，80 mg·kg-1·d-1， 2 d） to induce a hyperlipidemia-based ischemic heart disease model. After successful modeling， the rats were randomly divided into the model group， high， medium， and low dose groups of Gualou Xiebai Banxiatang， and the metoprolol group. The high， medium， and low dose groups of Gualou Xiebai Banxiatang were given Gualou Xiebai Banxiatang at 10.42， 5.21， 2.61 g·kg-1·d-1， respectively， while the metoprolol group was given metoprolol at 2.6 mg·kg-1·d-1. Both the normal and model groups were given an equivalent volume of physiological saline for 28 days. After the intervention， relevant tests were conducted， and serum was collected to measure heart function-related indicators. Hematoxylin-eosin （HE） and Masson staining were performed on ventricular tissue to observe pathological changes under a light microscope. Immunohistochemistry （IHC） was used to detect the positive expression of platelet endothelial cell adhesion molecule （CD31）. Enzyme-linked immunosorbent assay （ELISA） was used to detect the expression of N-terminal pro-brain natriuretic peptide （NT-proBNP） and VEGF. Western blot was used to detect the protein expression levels of PI3K/mTOR/HIF-1α/VEGF. ResultCompared with the normal group， the model group showed significantly increased serum levels of LDH， CK， CK-MB， NT-proBNP， and VEGF （P<0.01）， significantly increased collagen volume fraction （CVF） （P<0.01）， significantly decreased MVD （P<0.01）， and elevated protein expression levels of PI3K， mTOR， HIF-1α， and VEGF （P<0.05， P<0.01）. Compared with the model group， the metoprolol group had significantly lower serum levels of LDH， CK， CK-MB， and NT-proBNP （P<0.01）， significantly higher VEGF levels （P<0.01）， significantly decreased CVF （P<0.01）， significantly increased MVD （P<0.01）， and significantly increased protein expression levels of PI3K， mTOR， and VEGF （P<0.01）， with no statistically significant change in HIF-1α protein expression. Compared with the model group， the high and medium dose groups of Gualou Xiebai Banxiatang had decreased serum levels of LDH， CK， CK-MB， and NT-proBNP （P<0.05， P<0.01）， increased VEGF levels （P<0.05， P<0.01）， significantly reduced CVF （P<0.01）， increased MVD （P<0.05， P<0.01）， and significantly increased protein levels of PI3K， mTOR， HIF-1α， and VEGF （P<0.01）. In the low dose group of Gualou Xiebai Banxiatang， compared with the model group， serum levels of LDH and NT-proBNP were decreased （P<0.05）， VEGF was increased （P<0.05）. Moreover， CVF was decreased （P<0.05）， and the protein expression levels of PI3K， mTOR， HIF-1α， and VEGF were significantly increased （P<0.01）. ConclusionGualou Xiebai Banxiatang can improve cardiac function， reduce myocardial pathological damage， enhance endothelial cell function， promote myocardial microvascular formation， and upregulate the expression of PI3K， mTOR， HIF-1α， and VEGF proteins in myocardial tissue in rats with ischemic myocardial injury.

KLF7 Affects Development of Broiler Adipose Tissue by Inhibiting Hypoxia￣Inducible Factor 1 Alpha Transcription / 中国生物化学与分子生物学报

Krüppel-like factor 7 (KLF7) is a negative regulator of adipogenesis, whereas hypoxia-inducible factor 1 (HIF1) promotes anoxic-induced adipose tissue development in mammals. Our previous ChIP-seq analysis showed that one of the KLF7 binding peaks was present upstream of hypoxia-inducible factor 1 alpha (HIF1α), indicating that KLF7 may regulate HIF1α transcription. For this purpose, ChIP-PCR was used to verify ChIP-seq results, which showed that KLF7 directly bound to the HIF1α upstream region. Dual luciferase reporter and qRT-PCR results showed that KLF7 overexpression significantly decreased the luciferase reporter activity of HIF1α (- 4 432/- 4 182) (P < 0. 01) and inhibited HIF1α expression. After the deletion of KLF7 binding motif “TGCGCAGCAA” (- 4 300/-4 290) predicted by bioinformatics, the luciferase reporter activity of HIF1α (-4 432/-4 182) was significantly enhanced compared with wild-type plasmid (P<0. 01). Furthermore, Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF) at the age of 1-7 weeks from the 19

Role of HIF1α Regulatory Factors in Stem Cells

Hypoxia-inducible factor 1 (HIF1) is a master transcription factor that induces the transcription of genes involved in the metabolism and behavior of stem cells. HIF1-mediated adaptation to hypoxia is required to maintain the pluripotency and survival of stem cells under hypoxic conditions. HIF1 activity is well known to be tightly controlled by the alpha subunit of HIF1 (HIF1α). Understanding the regulatory mechanisms that control HIF1 activity in stem cells will provide novel insights into stem cell biology under hypoxia. Recent research has unraveled the mechanistic details of HIF1α regulating processes, suggesting new strategies for regulating stem cells. This review summarizes recent experimental studies on the role of several regulatory factors (including calcium, 2-oxoglutarate-dependent dioxygenase, microtubule network, importin, and coactivators) in regulating HIF1α activity in stem cells.

The expression of HIF-1 α in liver tissues in the rat model of paraquat poisoning / 中华急诊医学杂志

Objective To observe the levels of HIF-α and TGF-β in the liver tissue,change of serum transaminase in different phases after paraquat (PQ) toxicity and liver histopathology change in PQinduced liver toxicity of rats models in order to analyze the relationship between HIF-1 α and hepatic toxicity induced by PQ.Methods A total of 48 healthy SD rats were randomly (random number) assigned into 2 groups:PQ poisoning group (n =42,20％ PQ solution,50 mg/kg in 1mL) and control group (n =6,normal saline 1mL).Rats were separately sacrificed and liver tissue samples were harvested at 2,6,12,24,48,72 h and 120 h after PQ administered by gastric lavage.Arterial blood gas (ABG) analysis and serum alanine transaminase were assayed.Liver tissue HE and Masson staining and immunochemistry changes were also investigated.HIF-1α and TGF-β levels were detected by Western blot technique.Results Lactic acid level was significantly higher in PQ group than that in control group at 6 h after PQ exposure (P ＜ 0.05).The level of serum alanine transaminase was increased and significantly higher if PQ group than that in control group at 2 h after PQ poisoning (P ＜ 0.05).The level of HIF-1 α and TGF-β protein in the liver tissue were up-regulated significantly and higher in PQ group than those in control group at 2 h after PQ exposure (P ＜ 0.05).The hepatocytes necrosis and inflammatory cells infiltration were observed around portal area 2 h after PQ poisoning.At 12 h after PQ exposure,the periportal area filled with necrosis of hepatocytes and the necrosis began to extend,and huge amounts of inflammatory cell infiltration were found.Cord-like fibroplasia was found.All the histological changes were around central portal area and were enlarged gradually.Conclusions The results show that there are increased level of HIF-1 α in the early stage of PQ poisoning rats.The liver fibroplasia may be associated with increasing the level of TGF-β promoted by HIF-1α.

Radioresistance change and the mechanism of human esophaged cancer EC9706 cells in hypoxia / 中华放射医学与防护杂志

Objective To investigate the expression of hypoxia-inducible factor-1 alpha (HIF-1 α),vascular endothelial growth factor-A (VEGF-A) and vascular endothelial growth factor-D (VEGF-D)in hypoxic environment as well as the relationship between HIF-lα and VEGF-D.Methods Human esophageal cancer cell line EC9706 was cultured under hypoxia environment for 6,12 and 24 h,the cell radiosensitivity was evaluated by survival curve.HIF-1 α siRNA was constructed and transfected into human EC9706 cells.Protein expressions of HIF-1 α,VEGF-A and VEGF-D were analyzed by Western blot before and after RNA interference.Results EC9706 cells under hypoxia showed radioresistance with a SF2 of 0.62 higher than that of normoxic cells of 0.43.Moreover,the protein expressions of HIF-1α,VEGF-A and VEGF-D were all increased (F =205.24,227.88,130.55,P ＜0.05) due to hypoxia treatment.On the contrary,after HIF-1α siRNA transfer,the protein expressions of HIF-1α,VEGF-A and VEGF-D in EC9706 cells were not influenced by hypoxia treatment.Conclusions EC9706 cells in hypoxic environment was radioresistance,and the upexpressions of HIF1α,VEGF-A and VEGF-D may be involved.