The hypoxia-inducible factor-1α activates ectopic production of fibroblast growth factor 23 in tumor-induced osteomalacia

Tumor-induced osteomalacia （TIO） is a rare paraneoplastic syndrome in which ectopic production of fibroblast growth factor 23 （FGF23） by non-malignant mesenchymal tumors causes phosphate wasting and bone fractures. Recent studies have implicated the hypoxia-inducible factor-la （HIF-la） in other phosphate wasting disorders caused by elevated FGF23, including X-linked hypophosphatemic rickets and autosomal dominant hypophosphatemia. Here we provide evidence that HIF-la mediates aberrant FGF23 in TIO by transcriptionally activating its promoter. Immunohistochemical studies in phosphaturic mesenchymal tumors resected from patients with documented TIO showed that HIF-la and FGF23 were co-localized in spindle- shaped cells adjacent to blood vessels. Cultured tumor tissue produced high levels of intact FGF23 and demonstrated increased expression of HIF-la protein. Transfection of MC3T3-E1 and Saos-2 cells with a HIF-la expression construct induced the activity of a FGF23 reporter construct. Prior treatment of tumor organ cultures with HIF-la inhibitors decreased HIF-la and FGF23 protein accumulation and inhibited HIF-la-induced luciferase reporter activity in transfected cells. Chromatin immunoprecipitation assays confirmed binding to a HIF-la consensus sequence within the proximal FGF23 promoter, which was eliminated by treatment with a HIF-la inhibitor. These results show for the first time that HIF-la is a direct transcriptional activator of FGF23 and suggest that upregulation of HIF-la activity in TIO contributes to the aberrant FGF23 production in these patients.

Clinicopathological and Prognostic Significance of Hypoxia-inducible Factor-1 alpha in Lung Cancer: a Systematic Review with Meta-analysis

Hypoxia-inducible factor-1 alpha（HIF-1α） plays a vital role in the initiation, evaluation and prognosis in lung cancer. The prognostic value of HIF-1α reported in diverse study remains disputable. Accordingly, a meta-analysis was implemented to further understand the prognostic role of HIF-1α in lung cancer. The relationship between HIF-1α and the clinicopathological characteristics and prognosis of lung cancer were investigated by a meta-analysis. Pub Med and Embase were searched from their inception to January 2015 for observational studies. Fixed-effects or random-effects meta-analyses were used to calculate odds ratios and 95% confidence intervals of different comparisons. A total of 20 studies met the criteria. The results showed that HIF-1α expression in lung cancer tissues was significantly higher than that in normal lung tissues. Expression of HIF-1α in patients with squamous cell carcinoma was significantly higher than that of patients with adenocarcinomas. Similarly, non-small cell lung cancer（NSCLC） patients had higher HIF-1α expression than small cell lung cancer（SCLC） patients. Moreover, lymph node metastasized tissues had higher HIF-1α expression than non-lymph node metastasized tissues. A high level HIF-1α expression was well correlated with the expression of vascular endothelial growth factor and epidermal growth factor receptor in the NSCLC. Notably, NSCLC or SCLC patients with positive HIF-1α expression in tumor tissues had lower overall survival rate than patients with negative HIF-1α expression. It was suggested that HIF-1α expression may be a prognostic biomarker and a potential therapeutic target for lung cancer.

Phosphatase and tensin homology deleted in chromosome 10,hypoxia-inducible factor-1 alpha gene expression in colorectal adenoma and adenocarcinoma and their relation to vascular endothelial growth factor protein expression

To examine phosphatase and tensin homology deleted in chromosome 10 (PTEN),hypoxia-inducible factor-1 alpha (HIF-1 alpha) gene expressions and their relation to vascular endothelial growth factor(VEGF) protein expression in the patients with human colorectal adenomas and adenocarcinomas.Methods The expression of PTEN,HIF-1 alpha gene was detected by using in situ hybridization,and the VEGF expression levels by immunohistochemistry in colorectal adenomas and primary colorectal adenocarcinoma.Results Strong expression of HIF-1 alpha was detectable in the majority of colorectal dadenocarcinoma,particularly surrounding areas of necrosis in adenocarcinoma.PTEN,HIF-1 alpha mRNA and VEGF protein were positive in 51.6%,67.7% and 59.7% respectively in 62 cases of adenocarcinomas,and 77.8%,44.4% and 33.3% respectively in 18 cases of adenomas.The positive rate of VEGF was higher in the patients with colorectal adenocarcinomas than that in those with adenomas,whereas that of PTEN mRNA was contrary.HIF-1 mRNA expression was correlated significantly with lymph node metastasis,liver metastasis,Duke’s stage and recurrence.During colorectal tumor progression,the expression of HIF-1 alpha mRNA was positively correlated with the VEGF protein expression (χ2= 4.751 ,P<0.05),but negatively with the PTEN mRNA expression(χ2=21.84,P<0.01).Conclusion The absence or low expression of PTEN and the increased levels of HIF-1α and VEGF may paly an important role in carcinogenesis and progression of colorectal carcinoma.These results suggest that VEGF upregulated by HIF-1 alpha gene may be involved in angiogenesis of colorectal adenocarcinoma.4 refs,1 tab.

Hypoxia activates the hypoxia-inducible factor-1α/vascular endothelial growth factor pathway in a prostatic stromal cell line:A mechanism for the pathogenesis of benign prostatic hyperplasia

Background The development of benign prostatic hyperplasia(BPH)is closely related to hypoxia in the prostatic stroma,and the hypoxia-inducible factor-1α/vascular endothelial growth factor(HIF-1α/VEGF)pathway has been shown to significantly activate in response to hypoxia.The underlying mechanism for activation of this pathway in the pathogenesis of BPH remains unclear.Materials and methods We constructed HIF-1αoverexpression and knockdown BPH stromal(WPMY-1)and epithelial(BPH-1)cell lines,which were cultured under different oxygen conditions(hypoxia,normoxia,and hypoxia+HIF-1αinhibitor).Quantitative real-time polymerase chain reaction(qPCR)and Western blotting were applied to detect the expression of the HIF-1α/VEGF pathway.Cell proliferation and apoptosis were analyzed by Cell Counting Kit-8 and flow cytometry.We used the miRWalk 2.0 database and Western blotting to predict the potential miRNA that selectively targets the HIF-1α/VEGF pathway,and verified the prediction by qPCR and dual-luciferase assays.Results In a BPH stromal cell line(WPMY-1),the expression of VEGF was in accordance with HIF-1αlevels,elevated in the overexpression cells and decreased in the knockdown cells.Hypoxia-induced HIF-1αoverexpression,which could be reversed by a HIF-1αinhibitor.Moreover,the HIF-1αinhibitor significantly depressed cellular proliferation and promoted apoptosis in hypoxic conditions,assessed by Cell Counting Kit-8 and flow cytometry.However,in the BPH epithelial cell line(BPH-1),the expression level of HIF-1αdid not influence the expression of VEGF.Finally,a potential miRNA,miR-17-5p,regulating the HIF-1α/VEGF pathway was predicted from the miRWalk 2.0 database and Western blotting,and verified by qPCR and dual-luciferase assay.Conclusions In hypoxia,activation of the HIF-1α/VEGF pathway plays a crucial role in regulating cell proliferation in a BPH stromal cell line.Regulation by miR-17-5p may be the potential mechanism for the activation of this pathway.Regulation of this pathway may be involved in the pathogenesis of BPH.

Inhibition of the VEGF Expression and Cell Growth in Hepatocellular Carcinoma by Blocking HIF-1α and Smad3 Binding Site in VEGF Promoter

In order to investigate the inhibitory effects on the vascular endothelial growth factor （VEGF） expression and cell growth in hapatocellular carcinoma （HCC） by blocking HIF-1α and Smad3 binding site in the VEGF promoter, antisense oligodeoxynucleotides （ASODN） were designed to block HIF-1α and Smad3 binding site in the VEGF promoter. Different concentrations of ASODN and ODN were transfected into HCC cells respectively. The expression of VEGF mRNA and protein was detected by SABC, Western blot and RT-PCR techniques and the inhibitory effects on the expression of VEGF and cell growth of the HCC cells stimulated by the supernatants were determined by using MTT method. Immunohistochestry revealed that after co-inoculation of hepatocellular carcinoma cells with different concentrations of ODN and ASODN for 48 h, there was no significant difference in the expression of VEGF protein between ODN group and control group （P 〈0. 05）, but there was significant difference between ASODN group and control group （P〈 0.05）. At a concentration of 10 μmol/L ASODN, the difference was very significant （P〈0.01）. Western blot and RT-PCR revealed that, after treatment for 48 h at a concentration of 10 μmol/L, the integral gray levels and RNA odds were 59743.2±10412.5 and 0. 783±0. 032 in ODN group, and 38694.5±10925.1 and 0.468±0. 015 in ASODN group, respectively, with the difference being very significant （P〈0. 01）. Antisense ODN could inhibit the growth of HCC cells in a concentration-dependent manner. It was concluded that anti-gene technique of aiming at HIF-1α action site in the VEGF promoter could suppress the VEGF expression and inhibit HCC cell growth, and it is promising that anti-gene technique works as a new gene therapeutic tool for anti-angiogenesis of HCC.

Hypoxia-inducible factor-1 alpha regulates the role of vascular endothelial growth factor on pulmonary arteries of rats with hypoxia-induced pulmonary hypertension

Background Hypoxia-inducible factor-1α (HIF-1α) is one of the pivotal mediators in the response of lungs to decreased oxygen availability, and increasingly has been implicated in the pathogenesis of pulmonary hypertension. Vascular endothelial growth factor (VEGF), a downstream target gene of HIF-1α, plays an important role in the pathogenesis of hypoxic pulmonary hypertension and hypoxic pulmonary artery remodelling. In this study, we investigated the dynamic expression of HIF-1α and VEGF in pulmonary artery of rats with hypoxia-induced pulmonary hypertension. Methods Forty male Wistar rats were exposed to hypoxia for 0, 3, 7, 14 or 21 days. Mean pulmonary arterial pressure (mPAP), vessel morphometry and right ventricle hypertrophy index (RVHI) were estimated. Lungs were inflated and fixed for in situ hybridisation and immunohistochemistry. Results mPAP values were significantly higher than the control values after 7days of hypoxia [(18.4±0.4) mmHg, P<0.05]. RVHI developed significantly after 14 days of hypoxia. Expression of HIF-1α protein increased in pulmonary arterial tunica intima of all hypoxic rats. In pulmonary arterial tunica media, HIF-1α protein was markedly increased by day 3 (0.20±0.02, P<0.05), reached the peak by day 7, then declined after day 14 of hypoxia. HIF-1α mRNA increased significantly after day 14 of hypoxia (0.20±0.02, P<0.05). VEGF protein began to increase markedly after day 7 of hypoxia, reaching its peak around day 14 of hypoxia (0.15±0.02, P<0.05). VEGF mRNA began to increase after day 7 of hypoxia, then remained more or less stable from day 7 onwards. VEGF mRNA is located mainly in tunica intima and tunica media, whereas VEGF protein is located predominantly in tunica intima. Linear analysis showed that HIF-1α mRNA, VEGF and mPAP were correlated with hypoxic pulmonary artery remodelling. HIF-1α mRNA was positively correlated with VEGF mRNA and protein (P<0.01). Conclusion HIF-1α and VEGF are both involved in the pathogenesis of hypoxia-induced pulmonary hypertension in rats.

Hyperbaric oxygen intervention on expression of hypoxia-inducible factor-1 α and vascular endothelial growth factor in spinal cord injury models in rats

Background Hyperbaric oxygen （HBO） intervention is a main therapeutic method and the curative effect has been certified for spinal cord injury （SCI）, but the mechanisms of the neuroprotective effect of HBO on SCI remain elusive. This study aimed to observe the change in expression of hypoxia-inducible factor-1α （HIF-1α） and vascular endothelial growth factor （VEGF） after SCI at different time points and to investigate the neuroprotective mechanism of HBO on SCI in rats.

Expression of MMIF, HIF-1α and VEGF in Serum and Endometrial Tissues of Patients with Endometriosis

The aim of this study was to investigate the expression of macrophage migration inhibitory factor （MMIF）, hypoxia-inducible factor- 1 α（HIF- 1α ）and vascular endothelial growth factor （VEGF） in the serum and endometrial tissues of patients with endometriosis （EM） and the clinical significance. Eighty EM patients [American Reproductive Association stage Ⅰ （n=20）, stage Ⅱ （n=22）, stage Ⅲ （n=21） and stage Ⅳ （n=17）] were enrolled and divided into mild （10- 14 points, n=28）, moderate （16-24 points, n=27） and severe （26-30 points, n=25） dysmenorrhea groups. The control group included 40 healthy women of childbearing age who underwent routine healthcare examinations in the enrolment period. The expression of MMIF, HIF- 1α and VEGF in the serum and endometrial tissues was measured by enzyme-linked immunosorbent assay and Western blotting, respectively. Meanwhile, the sensitivity and specificity of serum MMIF, HIF-1α, and VEGF when separately used as single indexes or jointly used as one index were examined as well. The results showed that serum concentrations of MMIF, HIF-1α, and VEGF were significantly higher in EM patients than in controls （P〈0.05）. The expression of all three proteins in both serum and endometrial tissues increased significantly with the R-AFS stage （P〈0.05） and with dysmenorrheal severity （P〈0.05）. The sensitivity and specificity of the combined detection of serum MMIF, HIF-1α, and VEGF levels were significantly higher than those of single index detection （P〈0.05）. In conclusion, the expression of MMIF, HIF-1α, and VEGF in the serum and endometrial tissues may be used to assess the stage of EM and the severity of dysmenorrhea. Combined evaluation of MMIF, HIF-1α, and VEGF significantly improves the diagnostic sensitivity and specificity.

Expression and signifi cance of TLR4 and HIF-1α in pancreatic ductal adenocarcinoma

AIM:To investigate the expression of toll-like receptor(TLR) 4,nuclear factor-κB(NF-κB) p65 and hypoxiainducible transcription factor 1α(HIF-1α) in pancreatic ductal adenocarcinoma and their clinical significance.METHODS:The mRNA of TLR4 and HIF-1α were investigated by real-time polymerase chain reaction in 30 cases of pancreatic ductal adenocarcinoma and its adjacent tissues,and expression of TLR4,NF-κB p65 and HIF-1α protein were detected by immunohistochemistry in 65 cases of pancreatic ductal adenocarcinoma tissues and 38 cases of corresponding adjacent tissues.The relationship between TLR4 or HIF-1α and pathologic features,as well as the association between TLR4 and HIF-1α,were also analyzed.Kaplan-Meier method was used to assess the impact of expression of TLR4 and HIF-1α on survival of patients with pancreatic cancer.RESULTS:The relative quantif ication of TLR4 and HIF-1α mRNA in tumor tissues was 0.81±0.10 and 0.87±0.11,respectively,signif icantly higher than that in adjacent tissues(0.81±0.10 vs 0.70±0.16,P=0.002;0.87±0.11 vs 0.68±0.13,P=0.000).The protein expression of TLR4,NF-κB p65 and HIF-1α in tumor tissues was 69.20%,66.15% and 70.80%,respectively,being signif icantly higher than that in adjacent normal tissues(69.20% vs 39.50%,P=0.003;66.15% vs 31.58%,P=0.001;70.80% vs 36.80%,P=0.001).There was no signif icant correlation between TLR4 or HIF-1α expression and the age,gender,tumor location,the degree of tumor differentiation in the patients(P>0.05).However,there was signif icant correlation between the expression of TLR4 or HIF-1α and tumor size,lymph node metastasis,venous invasion and clinical staging(P<0.05).The expression of TLR4 and HIF-1α had a signif icant impact on survival of patients with pancreatic adenocarcinoma.CONCLUSION:TLR4,NF-κB p65 and HIF-1α are overexpressed in pancreatic adenocarcinoma,TLR4 may be partly involved in up-regulating HIF-1α,and both synergestically promote development of pancreatic adenocarcinoma.

Lichong decoction inhibits micro-angiogenesis by reducing the expressions of hypoxia inducible factor-1αand vascular endothelial growth factor in hysteromyoma mouse model

OBJECTIVE:To investigate the efficacy of Lichong decoction(LD)from Traditional Chinese Medicine,on micro-angiogenesis in a mouse model of hysteromyoma.METHODS:A mouse model of hysteromyoma was developed by orthotopic intrauterine injection of primary human myoma cells isolated from patients from the Beijing Obstetrics and Gynecology Hospital into CB-17 Scid mice.Mice were administered high-dose LD,low-dose LD,mifepristone or water(control)daily by gavage for 4 weeks.Uterine diameter and coefficient(uterine weight/body weight)were measured.Uterine morphology was assessed by light microscopy(hematoxylin and eosin)and transmission electron microscopy.Serum levels of estradiol,progesterone,follicle-stimulating hormone and luteinizing hormone(LH)were measured by enzyme-linked immunosorbent assay.Uterine protein expression of hypoxia inducible factor(HIF)-1α,CD31 and proliferating cell nuclear antigen(PCNA)was detected by immunohistochemistry.VEGF and HIF-1αm RNAs were quantified by RT-PCR.RESULTS:High-dose LD,low-dose LD and mifepristone reduced uterine diameter and coefficient,and attenuated the morphologic abnormalities associated with hysteromyoma.High-dose LD,low-dose LD and mifepristone inhibited hysteromyoma-induced micro-angiogenesis,as evidenced by a decrease in the number of new microvessels co-immunostaining for CD31 and PCNA(P<0.01).High-dose LD and mifepristone lowered serum levels of estradiol,progesterone and LH(P<0.05).High-dose LD,low-dose LD and mifepristone down-regulated HIF-1αm RNA and protein expressions and VEGF m RNA expression(P<0.01).CONCLUSION:The inhibition of hysteromyoma by LD may involve reductions in HIF-1αand VEGF expression and suppression of micro-angiogenesis.

Inhibition of β-elemene on the expressions of HIF-lα, VEGF and i NOS in diabetic rats model

AIM: To evaluate the effect of β-elemene on the expressions of hypoxia-inducible factor(HIF)-lα, vascular endothelial growth factor(VEGF) and inducible nitric oxide synthase(i NOS) in a streptozotocin(STZ) induced diabetic SpragueDawley(SD) rat model.METHODS: SD rats were administered an abdominal injection of STZ and induced to a diabetic model. After 6 wk course of diabetes, the treatment groups were given β-elemene through periocular and intravitreous injection separately and the control groups were given blank emulsion injection. HE staining was used to observe the morphology of retina. The m RNA expressions of HIF-1α, VEGF and i NOS was assayed by real-time polymerase chain reaction(PCR) and the protein expression was measured by Western blot and immunocytochemistry methods.RESULTS: The results indicated that the protein and m RNA expressions of HIF-1α, VEGF and i NOS after treated by β-elemene periocularly and intravitreally injections were all found to be reduced compared with the levels in the diabetic rats group(P<0.05). The inhibitory effect of intravitreal injection was more remarkable.CONCLUSION: The results show β-elemene protect the retina of diabetic rats from high glucose damage by downregulating the expression of HIF-1α, VEGF and iNOS.

急性脑出血患者血清HIF-1α与VEGF、Hsp70动态表达情况研究

目的:研究分析急性脑出血患者血清低氧诱导因子(hypoxia-inducible factor-1α,HIF-1α)与血管生长因子(vascular endothelial growth factor,VEGF)、热休克蛋白70(heat shock protein 70,Hsp70)动态表达情况。方法:将2014年3月至2015年4月我院急诊收治的35例急性脑出血患者,根据其出血量分为小量组、中量组、大量组,测定比较各分组人员发病后12 h、1 d、3 d、5 d、7 d的静脉血HIF-1α与VEGF、Hsp70差异,同时研究分析这3者与出血量之间的相关关系。结果:大量组患者不同时间点HIF-1α与VEGF、Hsp70指标均明显高于同时间点其他两组患者,P<0.05;单因素方差分析HIF-1α与VEGF、Hsp70与患者出血量间关系,均成正相关(r=0.563,P<0.05;r=0.771,P<0.05;r=0.602,P<0.05)。结论:HIF-1α、VEGF、Hsp70在急性脑出血患者中表达较高,在脑出血12 h后升高,并随着脑出血的发展呈现动态表达,且与出血量成正相关关系。

Downregulation of miR-491-5p promotes neovascularization after traumatic brain injury

Micro RNA-491-5 p(miR-491-5 p) plays an important role in regulating cell proliferation and migration;however,the effect of miR-491-5 p on neovascularization after traumatic brain injury remains poorly understood.In this study,a controlled cortical injury model in C57 BL/6 mice and an oxygen-glucose deprivation model in microvascular endothelial cells derived from mouse brain were established to simulate traumatic brain injury in vivo and in vitro,respectively.In the in vivo model,quantitative real-time-polymerase chain reaction results showed that the expression of miR-491-5 p increased or decreased following the intracerebroventricular injection of an miR-491-5 p agomir or antagomir,respectively,and the expression of miR-491-5 p decreased slightly after traumatic brain injury.To detect the neuroprotective effects of miR-491-p,neurological severity scores,Morris water maze test,laser speckle techniques,and immunofluorescence staining were assessed,and the results revealed that miR-491-5 p downregulation alleviated neurological dysfunction,promoted the recovery of regional cerebral blood flow,increased the number of lectin-stained microvessels,and increased the survival of neurons after traumatic brain injury.During the in vitro experiments,the potential mechanism of miR-491-5 p on neovascularization was explored through quantitative real-time-polymerase chain reaction,which showed that miR-491-5 p expression increased or decreased in brain microvascular endothelial cells after transfection with an miR-491-5 p mimic or inhibitor,respectively.Dual-luciferase reporter and western blot assays verified that metallothionein-2 was a target gene for miR-491-5 p.Cell counting kit 8(CCK-8) assay,flow cytometry,and 2′,7′-dichlorofluorescein diacetate(DCFH-DA) assay results confirmed that the downregulation of miR-491-5 p increased brain microvascular endothelial cell viability,reduced cell apoptosis,and alleviated oxidative stress under oxygen-glucose deprivation conditions.Cell scratch assay,Transwell assay,tube formation assay,and western blot assay results demonstrated that miR-491-5 p downregulation promoted the migration,proliferation,and tube formation of brain microvascular endothelial cells through a metallothionein-2-dependent hypoxia-inducible factor-1α/vascular endothelial growth factor pathway.These findings confirmed that miR-491-5 p downregulation promotes neovascularization,restores cerebral blood flow,and improves the recovery of neurological function after traumatic brain injury.The mechanism may be mediated through a metallothionein-2-dependent hypoxia-inducible factor-1α/vascular endothelial growth factor signaling pathway and the alleviation of oxidative stress.All procedures were approved by Ethics Committee of the First Affiliated Hospital of Chongqing Medical University,China(approval No.2020-304) on June 22,2020.

Expression levels and significance of hypoxia inducible factor-1 alpha and vascular endothelial growth factor in human colorectal adenocarcinoma

Background Hypoxia-inducible factor 1 (HIF-1), a transcription factor, is overexpressed in common human cancers and their metastases. This study aimed at determining the expression levels of HIF-1α and vascular endothelial growth factor (VEGF) in SW480 cells and in colorectal adenocarcinoma tissue and ascertaining whether HIF-1α and VEGF play important roles in tumor angiogenesis. Methods HIF-1α mRNA expression was analyzed using in situ hybridization and RT-PCR. HIF-1α and VEGF protein were detected in SW480 cells and colorectal adenomas and adenocarcinomas by immunohistochemistry using streptavidin/peroxidase (SP). Western blot was used to detect HIF-1α protein extracted from SW480 cells. Microvessel density (MVD) in colorectal carcinomas was determined by anti-CD_ 34 immunostaining in colorectal carcinomas. Results Optical density values representing HIF-1α mRNA expression levels were found to be significantly higher in SW480 cells in hypoxic conditions than in cells under normoxic conditions (P<0.05) or in hypoxic conditions but treated with genistein (P<0.05). The levels of HIF-1α and VEGF protein expression in SW480 cells were significantly higher in the hypoxia group than in the normoxia group (P<0.01, P<0.05, respectively) and hypoxia/genistein group (P<0.01, P<0.05, respectively). The positive expression rates of HIF-1α mRNA changed dramatically when comparing colorectal adenomas with adenocarcinomas of different Dukes’ stages (P<0.05). HIF-1α mRNA was also expressed at higher levels in adenocarcinomas than that in adenomas (P<0.01). HIF-1α protein expression correlated significantly with VEGF protein expression and MVD.Conclusions Hypoxia induces the expression of HIF-1α and VEGF in colorectal adenocarcinomas. HIF-1α may play an important role in angiogenesis and tumor progression by regulating the expression of VEGF in human colorectal carcinomas.

HIF-1α and MIF enhance neutrophil-driven type 3 immunity and chondrogenesis in a murine spondyloarthritis model

The hallmarks of spondyloarthritis(SpA)are type 3 immunity-driven inflammation and new bone formation(NBF).Macrophage migration inhibitory factor(MIF)was found to be a key driver of the pathogenesis of SpA by amplifying type 3 immunity,yet MIF-interacting molecules and networks remain elusive.Herein,we identified hypoxia-inducible factor-1 alpha(HIF1A)as an interacting partner molecule of MIF that drives SpA pathologies,including inflammation and NBF.HIF1A expression was increased in the joint tissues and synovial fluid of SpA patients and curdlan-injected SKG(curdlan-SKG)mice compared to the respective controls.Under hypoxic conditions in which HIF1A was stabilized,human and mouse neutrophils exhibited substantially increased expression of MIF and IL-23,an upstream type 3 immunity-related cytokine.Similar to MIF,systemic overexpression of IL-23 induced SpA pathology in SKG mice,while the injection of a HIF1A-selective inhibitor(PX-478)into curdlan-SKG mice prevented or attenuated SpA pathology,as indicated by a marked reduction in the expression of MIF and IL-23.Furthermore,genetic deletion of MIF or HIF1A inhibition with PX-478 in IL-23-overexpressing SKG mice did not induce evident arthritis or NBF,despite the presence of psoriasis-like dermatitis and blepharitis.We also found that MIF-and IL-23-expressing neutrophils infiltrated areas of the NBF in curdlan-SKG mice.These neutrophils potentially increased chondrogenesis and cell proliferation via the upregulation of STAT3 in periosteal cells and ligamental cells during endochondral ossification.Together,these results provide supporting evidence for an MIF/HIF1A regulatory network,and inhibition of HIF1A may be a novel therapeutic approach for SpA by suppressing type 3 immunity-mediated inflammation and NBF.

A Correlative Study between CT Perfusion Parameters and Angiogenesis in Rabbit VX2 Liver Tumors

Objective: The purpose of this study was to evaluate the correlation between CT perfusion parameters and the hypoxia-inducible factor-1 alpha (HIF-1α), vascular en-dothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP-2) and microvessel density (MVD) marked by CD34 molecular of rabbit VX2 liver tumors and to investigate the value of CT perfusion imaging in evaluating tumor angiogenesis. Material and methods: Twenty-four cases of rabbit VX2 liver tumor were performed by CT perfusion scanning. Hepatic artery perfusion (HAP), portal vein perfusion (PVP), total hepatic blood flow (THBF) and hepatic perfusion index (HPI) were measured by perfusion software. HIF-1α, VEGF and MMP-2 expression and MVD were detected in the 24 rabbit VX2 liver tumor tissue samples using immunohistochemical method. The correlation between the HIF-1α, VEGF, MMP-2 expression and MVD and CT perfusion parameters were analyzed. Results: Correlation analysis revealed that the expression of HIF-1α, MMP-2, MVD were positively related to the HAP, THBF, HPI (p < 0.01), but no relations with PVP (p > 0.05);and correlation analysis revealed that the expression of VEGF was positively related to the HAP, HPI (p 0.05). There was a positive relationship between the expression of HIF-1α, VEGF, MMP-2 and MVD (p < 0.01). Conclusions: CT perfusion imaging can reflect the blood perfusion of the rabbit VX2 liver tumors and evaluate the information of angiogenesis about tumors.

Time-dependent effect of combination therapy with erythropoietin and granulocyte colony-stimulating factor in a mouse model of hypoxic-ischemic brain injury

Erythropoietin （EPO） and granulocyte colony- stimulating factor （G-CSF） are likely to play broad roles in the brain. We investigated the effects of combination therapy with EPO and G-CSF in hypoxic- ischemic brain injury during the acute, subacute, and chronic phases. A total of 79 C57BL/6 mice with hypoxic-ischemic brain injury were randomly assigned acute （days 1-5）, subacute （days 11-15）and chronic （days 28-32） groups. All of them were treated with G-CSF （250 μg/kg） and EPO （5 000 U/kg） or saline daily for 5 consecutive days. Behavioral assessments and immunohistochemistry for angiogenesis, neuro- genesis, and astrogliosis were performed with an 8-week follow-up. Hypoxia-inducible factor-1 （HIF-1） was also measured by Western blot analysis. The results showed that the combination therapy with EPO and G-CSF in the acute phase significantly improved rotarod performance and forelimb-use symmetry compared to the other groups, while subacute EPO and G-CSF therapy exhibited a modest improvement compared with the chronic saline controls. The acute treatment significantly increased the density of CD31^＋（PECAM-1） and a-smooth muscle actin^＋ vessels in the frontal cortex and striatum, increased BrdU^＋/PSA- NCAM^＋ neurogenesis in the subventricular zone, and decreased astroglial density in the striatum. Furthermore, acute treatment significantly increased the HIF-1 expression in the cytosol and nucleus, whereas chronic treatment did not change the HIF-1 expression, consistent with the behavioral outcomes. These results indicate that the induction of HIF-1 expression by combination therapy with EPO and G-CSF synergistically enhances not only behavioral function but also neurogenesis and angiogenesis while decreasing the astroglial response in a time- dependent manner.