Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; Neovascularization, Physiologic ; Osteogenesis

The condylar cartilage was adapted to hypoxic conditions in vivo. However, condylar cartilage cells exposed in normoxia in vitro affect the chondrocyte phenotype and cartilage matrix formation. This condition also resulted in great difficulty in chondrocyte research. Culturing chondrocyte should be simulated in in vivo hypoxia environment as much as possible. The hypoxia-inducible factor-1α (HIF-1α) demonstrates an important transcription factor of adaptive response to hypoxic conditions. HIF-1α also plays an active role in maintaining homeostasis and function of chondrocytes. This review summarized current knowledge of the HIF-1α structure, signaling pathway, and mechanism of HIF-1α in the condylar cartilage repair.
Cartilage ; Chondrocytes ; Humans ; Hypoxia ; Hypoxia-Inducible Factor 1, alpha Subunit ; Signal Transduction

To investigate the effects of airway epithelial cells on macrophages chemotaxis and inflammatory cytokine expression under hypoxic conditions.
 Methods: Human bronchial epithelial cells (HBE) treated with different concentrations (0, 100, 200, 400, 800 μmol/L) of CoCl2 or transfected with HIF-1α siRNA were co-cultured with THP-1-derived M1 macrophages or M2 macrophages. The chemotactic effects on macrophages were analyzed by Transwell assay. The levels of TNF-α, IFN-γ, IL-4, IL-13 and IL-10 in the supernatants of macrophages were detected by ELISA, and HIF-1α or Cav-1 mRNA expression in HBE or macrophages was detected by RT-qPCR.
 Results: HBE cells promoted macrophages chemotaxis in a time- and concentration-dependent manner. Compared to un-transfected group, the chemotactic ability of HBE transfected with HIF-1α siRNA was significantly weakened (P<0.01). Under the same culture conditions, the chemotaxis of M2 macrophages was greater than that in THP1-derived M1 macrophages. The concentrations of TNF-α, IFN-γ, IL-4, IL-13 and IL-10 in the supernatants of macrophages were increased in a time-and concentration-dependent manner. The concentrations of TNF-α and IFN-γ were increased further after co-culturing for 8 and 12 h; while IL-4, IL-13 and IL-10 concentrations were increased further during 24 h of co-culture. The levels of cytokines in the supernatants of macrophages co-cultured with HBE and transfected with HIF-1α siRNA were significantly lower than those in un-transfected cells (P<0.05 or P<0.01). The reduction of TNF-α or IFN-γ was more obvious. The expression of HIF-1α or Cav-1 mRNA in HBE or macrophages was increased in a concentration-dependent manner after 8 or 12 h co-culture, which was significantly reduced when HBE was transfected with HIF-1α siRNA.
 Conclusion: Airway epithelial cells can enhance macrophages chemotaxis and pro-inflammatory cytokines expressions under hypoxic condition. HIF-1α and Cav-1 may be the important mediators in these processes.
Cell Hypoxia ; Chemotaxis ; Cytokines ; Epithelial Cells ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; Macrophages

OBJECTIVES: To investigate the expression and significance of jumonji domain-containing protein 2B (JMJD2B) and hypoxia-inducible factor-1α (HIF-1α) in non-Hodgkin's lymphoma (NHL) tissues in children. METHODS: Immunohistochemistry was used to detect the expression of JMJD2B and HIF-1α in lymph node tissue specimens from 46 children with NHL (observation group) and 24 children with reactive hyperplasia (control group). The relationship between JMJD2B and HIF-1α expression with clinicopathological characteristics and prognosis in children with NHL, as well as the correlation between JMJD2B and HIF-1α expression in NHL tissues, were analyzed. RESULTS: The positive expression rates of JMJD2B (87% vs 21%) and HIF-1α (83% vs 42%) in the observation group were higher than those in the control group (P<0.05). The expression of JMJD2B and HIF-1α was correlated with serum lactate dehydrogenase levels and the risk of international prognostic index in children with NHL (P<0.05). The expression of JMJD2B was positively correlated with the HIF-1α expression in children with NHL (r_s=0.333, P=0.024). CONCLUSIONS JMJD2B and HIF-1α are upregulated in children with NHL, and they may play a synergistic role in the development of pediatric NHL. JMJD2B can serve as a novel indicator for auxiliary diagnosis, evaluation of the severity, treatment guidance, and prognosis assessment in pediatric NHL.
Humans ; Child ; Hypoxia-Inducible Factor 1, alpha Subunit ; Prognosis ; Hypoxia ; Lymphoma, Non-Hodgkin

To study the expression of hypoxia inducible factor-1alpha (HIF-1alpha) protein in prostate cancer (Pca) and its biological significance, the expression of HIF-1alpha was assayed by means of immunohistochemical technique in 42 prostate cancer, 12 prostatic intraepithelial neoplasm (PIN) and 9 normal prostate tissue (NP) specimens. Western blot was used to examine the expression of HIF-1alpha in prostate cancer cell line (PC-3M) induced by different oxygen tension. HIF-1alpha expression was positive in 33 Pca and 9 PIN specimens, and the positive rate of HIF-1alpha was higher in distant metastasis patients than in patients without metastasis of prostate cancer (P<0.05), while there was no expression of HIF-1alpha in NP. The level of HIF-1alpha in PC-3M significantly increased with the decrease of oxygen tension (P<0.01). Overexpression of HIF-1alpha is the preliminary event of the formation of Pca, which may induce carcinoma into malignant phenotype. Thus it may serve as an early diagnosis marker and the novel target for Pca treatment.
Adenocarcinoma/*metabolism ; Cell Line, Tumor ; Hypoxia-Inducible Factor 1, alpha Subunit/*biosynthesis ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics ; Prostatic Neoplasms/*metabolism ; Tumor Markers, Biological/*biosynthesis

OBJECTIVE: To explore the mechanisms of angiogenesis in chronic myeloid leukemia (CML) through detecting the levels of angiogenesis-related factors secreted from K562 cells after overexpression and interference of HIF-1α gene in K562 cells. METHODS: The K562 cells were transfected by lentiviruses carried and interfered HIF-1α gene, then the transtected K562 cells with carried and interfered with HIF-1α gene were enrolled in overexpression and interference groups respectively, at the same time the K562 cells transfected by the empty virus were enrolled in control group. The cells were harvested after culture for 72 hours under normoxid condition. The transfection efficient in 3 groups was detected by fluorescence microscopy; the mRNA expression of HIF-1α gene and angiogenesis-related factors was detected by RT-PCR; the concentration of angiogenesis-related factors in the caltured supernatant was detected by ELISA. RESULTS: The optimal MOI of K562 cells transfected with lentivirus was 10 and the transfection efficiency was about 50%. The positive rate of transfection after screening by puromycin was more than 90%. The mRNA expression of ANG-I, ANG-II, TGF-α and VEGF in the interference group was lower than that in the over-expression group, and the TGF-β1 mRNA expression in the interference group was higher than in the over-expression group. The mRNA expression of ANG-I and VEGF in the interference group was lower than that in the control group. TGF-αdid not could be detected, and the culture supernatant concentration of ANG-I and TNF-α in the interference group was lower than in the over-expression group, while the VEGF concentration in the interference group was higher than that in the over-expression group. All of the above-mentioned differences were statistically significant (P＜0.05). CONCLUSION The positive K562 cells transfected with leutivirus have been harvested by screening with puromycin. The HIF-1α mRNA positively regulates the mRNA expression of ANG-1, ANG-2, TGF-α, VEGF in K562 cells, promotes the antocrine ability of ANG-1 and TNF-α, moreover not stimulates the autocrine of TGF-α, the up-regulation of HIF-1α expression can inhibit the expression TGF-β1 in K562 cells and the autocrine of TGF-β1.
Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; metabolism ; K562 Cells ; RNA, Messenger ; Vascular Endothelial Growth Factor A

OBJECTIVE: To investigate the effect of miR-186 inhibition on the expression of hypoxia-inducible factor-1α (HIF-α) and mitochondrial function in hypoxic vascular endothelial cells. METHODS: Human umbilical vein endothelial cells (HUVECs) cultured in routine or hypoxic conditions for 6 h were examined for the expression of miR-186. A miR-186 inhibitor was transfected in the HUVECs, and the cells were subsequently cultured in hypoxic condition for 6 h to observe the changes in the mitochondrial structure under an electron microscope. The changes in the mRNA and protein expressions of HIF-1α in response to miR-186 interference were tested using real-time fluorescent quantitative PCR and Western blotting. RESULTS: The expression of miR-18 was mildly increased in HUVECs after hypoxic exposure for 6 h (=0.0188). Interference of miR-186 expression obviously promoted the mRNA and protein expressions of HIF-1α in HUVECs. In hypoxic conditions, miR-186 interference significantly reduced mitochondrial damage in HUVECs as observed under electron microscope (=0.0297). CONCLUSIONS Inhibition of miR-186 protects vascular endothelial cells against hypoxic injuries by promoting HIF-α expression to lessen mitochondrial damage, suggesting the possibility of targeted miR-186 interference for treatment of hemorrhagic shock.
Cell Hypoxia ; Human Umbilical Vein Endothelial Cells ; Humans ; Hypoxia ; Hypoxia-Inducible Factor 1, alpha Subunit ; MicroRNAs ; Mitochondria ; Umbilical Veins

Drug metabolism is significantly affected under hypoxia environment with changes of pharmacokinetics, expression and function of drug-metabolizing enzymes and transporters. Studies have shown that hypoxia increases the release of a series of inflammatory cytokines which can modulate drug metabolism. Besides, both hypoxia inducible factor 1α (HIF-1α) and microRNA-mediated pathways play a role in regulating drug metabolism. This article reviewed the impact and single-factor modulating mechanisms of drug metabolism under hypoxia, and put forward the speculation and prospects of multi-factor modulating mechanisms.
Cell Hypoxia ; Humans ; Hypoxia ; Hypoxia-Inducible Factor 1, alpha Subunit ; physiology ; Membrane Transport Proteins ; physiology ; MicroRNAs ; physiology ; Pharmaceutical Preparations ; metabolism

Hypoxia occurs in chronic and acute vascular diseases and tumor formation. The ability of tumor cells to maintain a balance between an adaptation to hypoxia and cell death is regulated by a family of transcription factors called hypoxia-inducible factor 1 (HIF-1). Tumor hypoxia mediated by HIF-1 would facilitate the likelihood of resistance to chemotherapy and radiotherapy, proliferation, metastasis and the invasive potential; all of which culminate in a decrease in patient survival. And HIF-1 alpha subunit decides the activity of HIF-1, which is regulated by oxygen. So understanding the role of HIF in signal pathway, drug resistance mechanism and its feature is crucial for developing novel anticancer therapies. In recent years, more attentions have focused on HIF-1 alpha inhibitors. It is expected that development of more potent and selective HIF inhibitors will provide an effective treatment of cancer and other HIF-related diseases. So we will focus on the biological characteristics and mechanism of HIF-1 to review currently studied HIF-1 inhibitors.
Cell Death ; Humans ; Hypoxia-Inducible Factor 1 ; antagonists & inhibitors ; metabolism ; Hypoxia-Inducible Factor 1, alpha Subunit ; antagonists & inhibitors ; metabolism ; Neoplasms ; drug therapy ; Oxygen ; metabolism ; Signal Transduction

Gene Targeting ; Humans ; Hypoxia-Inducible Factor 1 ; Hypoxia-Inducible Factor 1, alpha Subunit ; pharmacology ; Neoplasm Invasiveness ; pathology ; physiopathology ; Neoplasm Metastasis ; physiopathology