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Hypoxia promotes angiogenesis, proliferation, invasion, and metastasis of pancreatic cancer. Essentially, all studies of the hypoxia pathway in pancreatic cancer research to date have focused on fully malignant tumors or cancer cell lines, but the potential role of hypoxia inducible factors (HIF) in the progression of premalignant lesions has not been critically examined. Here, we show that HIF2α is expressed early in pancreatic lesions both in human and in a mouse model of pancreatic cancer. HIF2α is a potent oncogenic stimulus, but its role in Kras-induced pancreatic neoplasia has not been discerned. We used the Ptf1aCre transgene to activate KrasG12D and delete Hif2α solely within the pancreas. Surprisingly, loss of Hif2α in this model led to markedly higher, rather than reduced, number of low-grade pancreatic intraepithelial neoplasia (mPanIN) lesions. These lesions, however, failed to progress to high-grade mPanINs, and displayed exclusive loss of β-catenin and SMAD4. The relationship among HIF2α, β-catenin, and Smad4 was further confirmed in vitro, where silencing of Hif2α resulted in reduced β-catenin and Smad4 transcript levels. Thus, with oncogenic Ras expressed in the pancreas, HIF2α modulates Wnt-signaling during mPanIN progression by maintaining appropriate levels of both Smad4 and β-catenin. Cancer Res; 73(15); 4781–90. ©2013 AACR.

Supplementry Figure 4 - PDF file 812K, HIF2� promotes B-catenin and Smad4 expression

Supplementary Figure 2 - PDF file 2100K, Normal pancreas development in Ptf1Cre;Hif2�f/f mice

Supplementary Figure 5 - PDF file 5613 K, Loss of Smad4 in PKH2 mPanINs

Supplementary Materials and Methods- PDF file 100K, Additional experimental procedures including Generation of Hif2�-floxed mouse line, Tissue processing and Immunostaining, Western Blot, and Small Interfering RNA transfection

Supplementary Figure 1 - PDF file 2170K, Generation of the Hif2�-floxed strain, and validation of Hif2� inactivation in the pancreas

Supplementary Tables S1-S2 - PDF file 73K, List of primary antibodies, along with the sources and working dilutions (S1); primers used in RT-PCR analyses (S2)

Supplementary Figure and Table Legends�- PDF file 93K, Legend for Supplemental Tables S1-S2 and Supplemental Figures S1-S5

Tailless (TLX, an orphan nuclear receptor) and hypoxia inducible factor-2α (HIF2α) are both essential for retinal astrocyte and vascular development. Tlx−/− mutation and astrocyte specific Hif2α disruption in Hif2αf/f/GFAPCre mice are known to cause defective astrocyte development and block vascular development in neonatal retinas. Here we report that TLX and HIF2α support retinal angiogenesis by cooperatively maintaining retinal astrocytes in their proangiogenic states. While Tlx+/− and Hif2αf/+/GFAPCre mice are phenotypically normal, Tlx+/−/Hif2αf/+/GFAPCre mice display precocious retinal astrocyte differentiation towards non-angiogenic states, along with significantly reduced retinal angiogenesis. In wild-type mice, TLX and HIF2α coexist in the same protein complex, suggesting a cooperative function under physiological conditions. Furthermore, astrocyte specific disruption of Phd2 (prolyl hydroxylase domain protein 2), a manipulation previously shown to cause HIF2α accumulation, did not rescue retinal angiogenesis in Tlx−/− background, which suggests functional dependence of HIF2α on TLX. Finally, the expression of fibronectin and VEGF-A is significantly reduced in retinal astrocytes of neonatal Tlx+/−/Hif2αf/+/GFAPCre mice. Overall, these data indicate that TLX and HIF2α cooperatively support retinal angiogenesis by maintaining angiogenic potential of retinal astrocytes.

Immunotherapy has become the breakthrough strategies for treatment of cancer in recent years. The application of messenger RNA in cancer immunotherapy is gaining tremendous popularity as mRNA can function as an effective vector for the delivery of therapeutic antibodies on immune targets. The high efficacy, decreased toxicity, rapid manufacturing and safe administration of mRNA vaccines have great advantages over conventional vaccines. The unprecedent success of mRNA vaccines against infection has proved its effectiveness. However, the instability and inefficient delivery of mRNA has cast a shadow on the wide application of this approach. In the past decades, modifications on mRNA structure and delivery methods have been made to solve these questions. This review summarizes recent advancements of mRNA vaccines in cancer immunotherapy and the existing challenges for its clinical application, providing insights on the future optimization of mRNA vaccines for the successful treatment of cancer.

Under normoxia, hypoxia inducible factor (HIF) α subunits are hydroxylated by PHDs (prolyl hydroxylase domain proteins) and subsequently undergo polyubiquitylation and degradation. Normal embryogenesis occurs under hypoxia, which suppresses PHD activities and allows HIFα to stabilize and regulate development. In this Primer, we explain molecular mechanisms of the oxygen-sensing pathway, summarize HIF-regulated downstream events, discuss loss-of-function phenotypes primarily in mouse development, and highlight clinical relevance to angiogenesis and tissue repair.

Tight junctions (TJs) form the structural basis of retinal pigment epithelium (RPE) barrier functions. Although oxidative stress contributes to age-related macular degeneration, it is unclear how RPE TJ integrity is controlled by redox balance. In this study, we investigated the protective roles of nuclear factor erythroid 2-related factor 2 (NRF2), a transcription factor, and heme oxygenase-1 (HO1), a heme-degrading enzyme encoded by the NRF2 target gene HMOX1.ARPE19 cell cultures and mice, including wild-type, Nrf2-/-, and RPE-specific NRF2-deficient mice, were treated with chemicals that impose oxidative stress or impact heme metabolism. In addition, NRF2 and HO1 expression in ARPE19 cells was knocked down by siRNA. TJ integrity was examined by anti-zonula occludens-1 staining of cultured cells or flatmount RPE tissues from mice. RPE barrier functions were evaluated by transepithelium electrical resistance in ARPE19 cells and immunofluorescence staining for albumin or dextran in eye histological sections.TJ structures and RPE barrier functions were compromised due to oxidant exposure and NRF2 deficiency but were rescued by HO1 inducer. Furthermore, treatment with HO1 inhibitor or heme precursor is destructive to TJ structures and RPE barrier properties. Interestingly, both NRF2 and HO1 were upregulated under oxidative stress, probably as an adaptive response to mitigate oxidant-inflicted damages.Our data indicate that the NRF2-HO1 axis protects TJ integrity and RPE barrier functions by driving heme degradation.

In mice, retinal vascular and astrocyte networks begin to develop at birth, expanding radially from the optic nerve head (ONH) towards the retinal periphery. The retinal vasculature grows towards the periphery ahead of differentiated astrocytes, but behind astrocytic progenitor cells (APCs) and immature astrocytes. Endothelial cell specific Vegfr-2 disruption in newborn mice not only blocked retinal vascular development but also suppressed astrocytic differentiation, reducing the abundance of differentiated astrocytes while causing the accumulation of precursors. By contrast, retinal astrocytic differentiation was accelerated by the exposure of wild-type newborn mice to hyperoxia for 24 hours, or by APC specific deficiency in hypoxia inducible factor (HIF)−2α, an oxygen labile transcription factor. These findings reveal a novel function of the retinal vasculature, and imply that in normal neonatal mice, oxygen from the retinal circulation may promote astrocytic differentiation, in part by triggering oxygen dependent HIF-2α degradation in astrocytic precursors.

Metabolic gene variants, smoking, and alcohol consumption are important upper digestive tract cancer (UDTC) risk factors. However, the gene-gene and gene-environment interactions remain unclear. A case-control study in a high incidence area for upper digestive tract cancer was conducted in China. DNA was extracted from buffy coat samples for PCR or PCR-restriction fragment length polymorphism. Smoking and alcohol drinking status was determined by questionnaires. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the associations. After adjusting for confounding factors, smoking increased esophageal cancer (EC), gastric cardia cancer (GCC) and gastric antral carcinoma (GAC) risk by 3.594, 4.658, and 3.999-fold, respectively. Alcohol consumption increased EC, GCC and GAC risk by 1.953, 2.442 and 1.765-fold, respectively. The cytochrome P4501A1 (CYP1A1) rs4646903 T>C polymorphism increased GCC risk, the cytochrome P4502E1 (CYP2E1) rs2031920 C>T polymorphism increased EC risk, while the GSTM1 null genotype decreased EC risk. An association existed between the following: CYP1A1 rs4646903 and smoking in EC, GCC and GAC; CYP1A1 rs4646903 and alcohol consumption in EC and GCC; CYP2E1 rs2031920 and smoking in EC, GCC and GAC and CYP2E1 rs2031920 and alcohol consumption in EC and GCC. No association was observed between CYP1A1 and CYP2E1. The glutathione S-transferase mu 1 (GSTM1) null genotype decreased EC risk (OR=0.510). Smoking/drinking are upper digestive tract cancer risk factors. The CYP1A1 rs4646903 and CYP2E1 rs2031920 polymorphisms were risk factors of GCC or EC, and the GSTM1 null genotype may serve a protective role against EC. The results of the present study indicated that gene-environment interactions increase the risk of UDTC.

Vascular pruning is crucial for normal development, but its underlying mechanisms are poorly understood. Here, we report that retinal vascular pruning is controlled by the oxygen-sensing mechanism in local astrocytes. Oxygen sensing is mediated by prolyl hydroxylase domain proteins (PHDs), which use O(2) as a substrate to hydroxylate specific prolyl residues on hypoxia inducible factor (HIF)-α proteins, labeling them for polyubiquitylation and proteasomal degradation. In neonatal mice, astrocytic PHD2 deficiency led to elevated HIF-2α protein levels, expanded retinal astrocyte population and defective vascular pruning. Although astrocytic VEGF-A was also increased, anti-VEGF failed to rescue vascular pruning. However, stimulation of retinal astrocytic growth by intravitreal delivery of PDGF-A was sufficient to block retinal vascular pruning in wild-type mice. We propose that in normal development, oxygen from nascent retinal vasculature triggers PHD2-dependent HIF-2α degradation in nearby astrocytic precursors, thus limiting their further growth by driving them to differentiate into non-proliferative mature astrocytes. The physiological limit of retinal capillary density may be set by astrocytes available to support their survival, with excess capillaries destined for regression. This article has an associated ‘The people behind the papers’ interview.

We quantified the serum levels of 34 cytokines/chemokines in 30 patients with SARS-CoV-2 infection. Elevated levels of IP-10 and IL-7 were detected in the acute and convalescent stages of the infection and were highly associated with disease severity.

Piwi-interacting RNAs (piRNAs) dysregulation occurs frequently in extensive cancers. However, there was no report about piRNA expression in esophageal cancer (EC). In this study, the expression levels of piR-823 and DNMT1, DNMT3A, DNMT3B were detected in 54 pairs of ESCC tissues and adjacent normal tissues using the quantitative real-time polymerase chain reaction method. Pearson's chi-squared test and receiver operating characteristic curves were established to evaluate the diagnostic and prognostic value of piR-823 in ESCC. Spearman's correlation analysis was used to evaluate the association between piR-823 and DNMTs. We found that piR-823 was significantly upregulated in ESCC tissues compared with matched normal tissues (P = 0.0213), the level of piR-823 was significantly associated with lymph node metastasis (P = 0.042). The ROC curve analysis of piR-823 expression level yielded an area under the ROC curve value of 0.713 (P = 0.0001). DNMT3B was upregulated in ESCC tissues compared with matched normal tissues (P = 0.0286). There was an obvious positive correlation between piR-823 and DNMT3B expression (r = 0.6420, P < 0.0001). In conclusion, for the first time, we provided evidence about piRNA expression in EC. piRNA-823 and DNMT3B were both upregulated in ESCC and positively correlated with each other, suggesting the tumor oncogenic role of piR-823 in ESCC to epigenetically induce aberrant DNA methylation through DNMT3B. In addition, piRNA-823 showed high specificity in detecting ESCC and higher piRNA-823 level indicated higher risk of lymph node metastasis, suggesting its diagnostic and prognostic biomarker potential.

To investigate the clinical characteristics and clinical prognostic factors of patients with acute lymphoblastic leukemia (ALL).Ninety-six ALL patients in our hospital from June 2012 to August 2014 were selected and their clinical data were collected. The related clinical data of patients were recorded, and the relation between clinical characteristics and therapeutic efficacy was analyzed. The COX analysis was used to reveal the risk factors affecting the patient's OS and DFS time.Among 96 ALL patients, 65 patients achieved complete remission (CR) after treatment. The age, immunophenotype, central nervous system leukemia (CNSL) and peripheral blood WBC count correlated with complete remission (P0.05). The age, WBC count, platelet level, immune typing and consolidation therapy were the prognostic factors (P0.05), the 2 year OS rate was influenced by age, WBC count, CD34 and consolidation therapy (P0.05), the 2 year DFS rate was influenced by age, CD34 and consolidation therapy (P0.05).Age, WBC counts, CD34 and consolidated treatment after remission are prognostic factors for ALL patients, which has guiding significance for clinical treatment of ALL.

In model of image-retrieval based on bag-of-features, a large number of information is lost during the process of quantizing the high-dimensional SIFT features as visual words. It leads to the teeming of errors matching feature points. To address this problem, this paper couples the color information into the BoF model as a complement to sift features, two different features are extracted to represent the same interest region and a visual pair is obtained by quantizing the descriptor pair with two independent codebooks. What’s more, we weight similarity degree of images by using the saliency area of image to decrease the semantic gap between low-level features and high-level expressions. We show that such an approach can significantly outperform matching results compared with traditional model of bag-of-features on Holiday dataset. Furthermore, our strategy of weighting based saliency further improved our performance in image-retrieval.

To explore the correlation of Th17 cell rate and IL-17 level with pathogenetis of multiple myeloma(MM).Forty-five cases of MM were enrolled in MM group, while 45 healthy volunteers were selected in control group. The rate of Th17 cells, levels of IL-17 and β2-microglobulin(β2-MG) in patients subgrouping according to ISS staging and treatment were detected by using flow cytometer and IL-17 assay kit. The correlation of Th17 cell rate and IL-17 level with MM was analyzed.The rate of Th17 cells and level of IL-17 in MM group were higher than those in control group(P0.05), the rate of Th17 cells and level of IL-17 in ISS III stage patients were higher than those in ISS I and II stage patients(P0.05); the rate of Th17 cells and level of IL-17 in ISS I and ISS II stage patients were not significant difference (P0.05); the rate of Th17 cells and level of IL-17 in firstly treated, retreated/refractory patients were significantly higher than those in patients with effective treatment(P0.05), while the rate of Th17 cells and level of IL-17 between firstly treated patients and retreated/refractory patients were not significant difference (P0.05). The Th17 rate and IL-17 level in MM patients positively correlated with β2-MG level (r=0.422, r=0.416, P0.05).The obvious increase of Th17 rate, IL-17 and β2-MG levels closely relates with pathogenesis of MM. The Th17 rate and IL-17 level may be used as important evidence for evaluation of ISS stage and therapeutic efficacy of MM.

The dynamic, heterogeneity and complexity make cloud platform much less credible. As a vital level in cloud computing platform, IaaS is very important to improve the trustworthy degree of cloud. In this paper, we explore this area, we identify the fundamental function provided by the trusted IaaS, we identify the indispensable tasks completed by the trusted IaaS, and then we propose a foundation framework for establishing trusted IaaS. Finally, we gave a conclusion and the direction of future works.

Background: Our previous studies demonstrate that the major histocompatibility complex (MHC) is associated with the progression of esophageal squamous cell carcinoma (ESCC). HLA-DQA1, which belongs to the MHC Class II family, may be a potential biomarker in ESCC progression. However, the association between HLA-DQA1 and ESCC in high-incidence area of northern China has not been well characterized. The purpose of this study is to investigate the relationship of HLA-DQA1 expression with the progression and prognosis of ESCC. Methods: We analyzed the expression profiles of HLA-DQA1 in esophageal cancer (EC) samples in the TCGA database and validated HLA-DQA1 expression by immunohistochemistry, western blotting, and quantitative reverse-transcription polymerase chain reaction in matched EC and normal tissues, respectively. The correlation between HLA-DQA1 expression and clinicopathologic characteristics of ESCC was further analyzed. Result: Immunohistochemical analysis indicated that the expression level of HLA-DQA1 in ESCC tissues was significantly higher than the matched normal tissues (P 4 cm were associated with higher HLA-DQA1 expression levels. A prognostic significance of HLA-DQA1 was also found by the Log-rank method, in which high expression of HLA-DQA1 was correlated with a shorter overall survival time. The receiver operating characteristic (ROC) curve analysis yielded the area under the ROC curve value of 0.693. Univariate and multivariate analyses also suggest that high expression of HLA-DQA1 is a potential indicator for poor prognosis of ESCC. Conclusions: Our results demonstrate that HLA-DQA1 plays an important role in ESCC progression and may be a biomarker for ESCC diagnosis and prognosis, as well as a potential target for the treatment of patients with ESCC.

To study the clinical features of of patients with primary central nervous system lymphoma(PCNSL) and their influence on prognosis.Forty-two cases of PCNSL hospitallized in our hospital from January 2012 to December 2015 were selected, and the laboratory analysis, imaging examination, bone marrow analysis and pathological examination all were performed, 26 cases were treated by lumbar puncture combined with intrathecal injection of drugs (Ara C, dexamethason and methotrexate), 8 cases were treated by methotrexate combined with rituximab, 8 cases voluntanly abandon treatment after being diagnosed as PCNSL.Headache accrued in 12 cases, diplopia in 2 cases, dizziness in 6 cases, limb weakness in 10 cases, amnesia in 2 cases, inhibited speech in 4 cases.Out of 42 patients 4 cases of peripheral T cell lymphoma, 38 cases of B cell lymphoma; 30 cases of multiple lesions, 12 cases of solitary lesions, 8 cases of corpus callosum, 8 cases of thalamus, 8 cases of frontal lobe, parietal lobe, temporal lobe, thalamus and other lesions, 2 cases of hydrocephalus, 2 cases of cerebral hemorrhage; and the patients HIV were negative. 8 cases erythrocyte sedimentation rate were faster, IgG, IgE and IgM levels increased to varying degrees in 42 cases, and the blood routine, liver function and blood coagulation examinations showed normal; There was no significant difference in the influence of the lumbar injection, methotrexate dose, radiation therapy, and hematopoietic stem cell transplantation on survival time(P0.05); but there was significant difference in the influence of rituximab and number of lesions on survival time (P0.05); there were significant differences in the effects of age and protein content in cerebrospinal fluid on therapeutic effecacy(P0.05).There is no significant difference in the imaging examination and clinical manifestation between PCNSL and other intracranial tumors. The lumbar puncture is an effective way to identify, the age, cerebrospinal fluid protein and the number of lesions are the adverse factors influencing the prognosis.

The dynamic range of the luminance of the scenes surrounding us are mostly very wide in all time of a day. High performance cameras were designed to capture these luminance with longer digits in their pixels. However, conventional displays can only render pixels with eight bits per channel, making the devices the bottleneck among the whole pipeline. As an effort to narrow this gap, this paper presents an improved strategy based on existing tone reproduction algorithms. It aims to provide good luminance range compression while preserving fine details of the contents. Experiments demonstrate that the presented algorithm can be successfully applied to the rendition of both natural and synthesized scenes, with high dynamic range or low radiance.

In this paper, a method of detecting adult images based on AdaBoost was proposed. We focused on the detection of the adult images that have naked breasts or naked genitalia. By using basic and rotated Haar-like features extracted from the samples in the training set, we trained a cascade detector. The detector would classify the image whether to be a pornographic one or not. The results showed that this method achieved a high detection rate and a low false alarm rate.

Our project focuses on the emotional face evoked EEG signal recognition. Since EEG signals contain enough information to separate different emotional facial expressions. Thus we propose a new approach which is based on global field power on EEG signal classification. In order to perform this result, firstly, we gather a dataset with EEG signals. This is done by measuring EEG signals from people aged 20-30 that are stimulated by emotional facial expressions (Happy, Neutral, Sad). Secondly, the collected EEG signals are preprocessed through using noise reduction method. And then select features by principal component analysis (PCA) to filter out redundant information. Finally, using fisher classifier and a 10-fold cross validation method for training and testing, a good classification rate is achieved when combination local max global field power EEG signals. The rate is 90.49%.

In this paper, a natural image compression method is proposed based on independent component analysis (ICA) and visual saliency detection. The proposed compression method learns basis functions trained from data using ICA to transform the image at first; and then sets percentage of the zero coefficient number in the total transforming coefficients. After that, transforming coefficients are sparser which indicates further improving of compression ratio. Next, the compression method performance is compared with the discrete cosine transform (DCT). Evaluation through both the usual PSNR and Structural Similarity Index (SSIM) measurements showed that proposed compression method is more robust to DCT. And finally, we proposed a visual saliency detection method to detect automatically the important region of image which is not or low compressed while the other regions are highly compressed. Experiment shows that the method can guarantee the quality of important region effectively.

Polycythemia is often associated with erythropoietin (EPO) overexpression and defective oxygen sensing. In normal cells, intracellular oxygen concentrations are directly sensed by prolyl hydroxylase domain (PHD)–containing proteins, which tag hypoxia-inducible factor (HIF) α subunits for polyubiquitination and proteasomal degradation by oxygen-dependent prolyl hydroxylation. Here we show that different PHD isoforms differentially regulate HIF-α stability in the adult liver and kidney and suppress Epo expression and erythropoiesis through distinct mechanisms. Although Phd1−/− or Phd3−/− mice had no apparent defects, double knockout of Phd1 and Phd3 led to moderate erythrocytosis. HIF-2α, which is known to activate Epo expression, accumulated in the liver. In adult mice deficient for PHD2, the prototypic Epo transcriptional activator HIF-1α accumulated in both the kidney and liver. Elevated HIF-1α levels were associated with dramatically increased concentrations of both Epo mRNA in the kidney and Epo protein in the serum, which led to severe erythrocytosis. In contrast, heterozygous mutation of Phd2 had no detectable effects on blood homeostasis. These findings suggest that PHD1/3 double deficiency leads to erythrocytosis partly by activating the hepatic HIF-2α/Epo pathway, whereas PHD2 deficiency leads to erythrocytosis by activating the renal Epo pathway.

To explore the clinical value of arsenious acid (H3AsO3) for treating patients with acute promyelocytic leukemia (APL).A total of 86 patients with APL were randomly divided into experimental group (43 cases) and control group (43 cases). The control group was treated by all trans retinoic acid combined with chemotherapy, the experimental group were treated by arsenous acid on the basis of the control group.The overall response rate (ORR) in experimental group (100.00%) was significantly higher than that in control group (88.37%) (P0.05). The time of returm to complete remission in experimental group (30.86 ± 4.34) was better than that in control group (42.42 ± 7.10) d (P0.05). The time of return to normal levels of peripheral WBC count (20.86 ± 9.28) × 10⁹/L, hemoglobin count (68.62 ± 14.97) g/L and thrombocyte count in experimental group obviously less than that in control group (P0.05). The rates of high white blood syndrome (HWBS), disseminated intravascular coagulation (DIC) in experimental group were lower than that in control group (P0.05). The survival rates of 2 and 3 years in experimental group were higher than that in control group (P0.05). The recurrence rate after treatment in experimental group was lower than that in control group (P0.05). The application of arsenious acid was main factor for patients survival (P0.05).Arsenious acid can improve the clinical efficacy for the patients with acute promyelocytic leukemia, and reduce the complication, therefore it is worthy of application in clinic.

Phosphoinositide 3-kinase (PI3K) is activated by transmembrane tyrosine kinases such as vascular endothelial growth factor (VEGF) receptors and Tie2 (tunica intima endothelial kinase 2), both of which are key regulators of vascular development. However, the in vivo role of PI3K during developmental vascularization remains to be defined. Here we demonstrate that mice deficient in the p110α catalytic subunit of PI3K display multiple vascular defects, including dilated vessels in the head, reduced branching morphogenesis in the endocardium, lack of hierarchical order of large and small branches in the yolk sac, and impaired development of anterior cardinal veins. These vascular defects are strikingly similar to those in mice defective in the Tie2 signaling pathway. Indeed, Tie2 protein levels were significantly lower in p110α-deficient mice. Furthermore, RNA interference of p110α in cultured endothelial cells significantly reduced Tie2 protein levels. These findings raise the possibility that PI3K may function as an upstream regulator of Tie2 expression during mouse development.

Mouse embryogenesis is dose sensitive to vascular endothelial growth factor-A (VEGF-A), and mouse embryos partially deficient in VEGF-A die in utero because of severe vascular defects. In this study, we investigate the possible causes that underlie this phenomenon. Although the development of vascular defects in VEGF-A-deficient embryos seems to suggest that endothelial differentiation depends on the presence of a sufficient level of VEGF-A, we were surprised to find that endothelial differentiation per se is insensitive to a significant loss of VEGF-A activity. Instead, the development of the multipotent mesenchymal cells, from which endothelial progenitors arise in the yolk sac, is most highly dependent on VEGF-A. As a result of VEGF-A deficiency, dramatically fewer multipotent mesenchymal cells are generated in the prospective yolk sac. However, among the small number of mesenchymal cells that do enter the prospective yolk sac, endothelial differentiation occurs at a normal frequency. In the embryo proper, vasculogenesis is initiated actively in spite of a significant VEGF-A deficiency, but the subsequent steps of vascular development are defective. We conclude that a full-level VEGF-A activity is not critical for endothelial specification but is important for two distinct processes before and after endothelial specification: the development of the yolk sac mesenchyme and angiogenic sprouting of blood vessels.

Deficiencies in prolyl hydroxylase domain proteins (PHDs) may lead to the accumulation of hypoxia-inducible factor-α proteins, the latter of which activate local angiogenic responses by paracrine mechanisms. Here, we investigate whether a keratinocyte-specific PHD deficiency may promote vascular survival and growth in a distantly located ischemic tissue by a remote signaling mechanism. We generated mice that carry a keratinocyte-specific Phd2 knockout (kPhd2KO) and performed femoral artery ligation. Relative to wild-type controls, kPhd2KO mice displayed improved vascular survival and arteriogenesis in ischemic hind limbs, leading to the accelerated recovery of hindlimb perfusion and superior muscle regeneration. Similar protective effects were also seen in type 1 and type 2 diabetic mice. Molecularly, both abundance of hypoxia-inducible factor-1α protein and expression of vascular endothelial growth factor-A were increased in epidermal tissues of kPhd2KO mice, accompanied by increased plasma concentration of vascular endothelial growth factor-A. Contrary to kPhd2KO mice, which are PHD2 deficient in all skin tissues, localized kPhd2KO in hindlimb skin tissues did not have similar effects, excluding paracrine signaling as a major mechanism. Confirming the existence of remote effects, hepatocyte-specific Phd2 knockout also protected hind limbs from ischemia injury. These data indicate that vascular survival and growth in ischemia-injured tissue may be stimulated by suppressing PHD2 in a remotely located tissue and may provide highly effective angiogenesis therapies without the need for directly accessing target tissues.

In order to use enterprises' distribution data effectively and maximize their social and economic values, a multi-level grid partition method for enterprise distribution data is proposed which divides the voluminous data into reasonable size. This method uses the provinces or municipalities of nationwide as the coarsest division, then a quad-tree is constructed to partition the points of enterprises according to their locations. Each node in the quad-tree has a limit of points, when the number of points in a node beyond the limit, the node is divided into four nodes with roughly the same number of points in each quadrant. This process proceeds recursively until no node contains points more than the limit. Enterprise distribution data of Harbin is used in experiments to test the feasibility and effectiveness of this method, the results of the experiments show that the enterprises distribution data are divided rapidly and accurately to the grid, which improve the applicability of the data and the convenience of data integration.

Hypoxia promotes angiogenesis, proliferation, invasion, and metastasis of pancreatic cancer. Essentially, all studies of the hypoxia pathway in pancreatic cancer research to date have focused on fully malignant tumors or cancer cell lines, but the potential role of hypoxia inducible factors (HIF) in the progression of premalignant lesions has not been critically examined. Here, we show that HIF2α is expressed early in pancreatic lesions both in human and in a mouse model of pancreatic cancer. HIF2α is a potent oncogenic stimulus, but its role in Kras-induced pancreatic neoplasia has not been discerned. We used the Ptf1aCre transgene to activate KrasG12D and delete Hif2α solely within the pancreas. Surprisingly, loss of Hif2α in this model led to markedly higher, rather than reduced, number of low-grade pancreatic intraepithelial neoplasia (mPanIN) lesions. These lesions, however, failed to progress to high-grade mPanINs, and displayed exclusive loss of β-catenin and SMAD4. The relationship among HIF2α, β-catenin, and Smad4 was further confirmed in vitro, where silencing of Hif2α resulted in reduced β-catenin and Smad4 transcript levels. Thus, with oncogenic Ras expressed in the pancreas, HIF2α modulates Wnt-signaling during mPanIN progression by maintaining appropriate levels of both Smad4 and β-catenin. Cancer Res; 73(15); 4781–90. ©2013 AACR.

Here we report that C-terminal Src kinase (Csk), a tyrosine kinase that negatively regulates the activity of Src and related kinases, is important for vascular development. In Csk–/– embryos, although vascular tubules were formed and organized into capillary-like networks during the initial genesis of blood vessels, the vessels failed to engage in normal sprout formation. In chimeric embryos containing both wild-type and Csk–/– cells, the presence of wild-type cells enabled Csk–/– endothelial cells to participate in branching morphogenesis. We suggest that wild-type cells may have supplied an angiogenic factor absent in Csk–/– cells. Despite the partial rescue of vascular development in chimeric embryos, the embryos failed to form vitelline vessels and died at E9.5. These results indicate that Csk is required both for angiogenic sprouting and vascular remodeling.

Background— Vascular endothelial growth factor receptor-1 (VEGFR-1/Flt-1) is a potential therapeutic target for cardiovascular diseases, but its role in angiogenesis remains controversial. Whereas germline Vegfr-1 −/− embryos die of abnormal vascular development in association with excessive endothelial differentiation, mice lacking only the kinase domain appear healthy. Methods and Results— We performed Cre- lox P–mediated knockout to abrogate the expression of all known VEGFR-1 functional domains in neonatal and adult mice and analyzed developmental, pathophysiological, and molecular consequences. VEGFR-1 deficiency promoted tip cell formation and endothelial cell proliferation and facilitated angiogenesis of blood vessels that matured and perfused properly. Vascular permeability was normal at the basal level but elevated in response to high doses of exogenous VEGF-A. In the postinfarct ischemic cardiomyopathy model, VEGFR-1 deficiency supported robust angiogenesis and protected against myocardial infarction. VEGFR-1 knockout led to abundant accumulation of VEGFR-2 at the protein level, increased VEGFR-2 tyrosine phosphorylation transiently, and enhanced serine phosphorylation of Akt and ERK. Interestingly, increased angiogenesis, tip cell formation, vascular permeability, VEGFR-2 accumulation, and Akt phosphorylation could be partially rescued or suppressed by one or more of the following manipulations, including injection of the VEGFR-2 selective inhibitor SU1498, anti-VEGF-A, or introduction of Vegfr-2 +/− heterozygosity into Vegfr-1 somatic knockout mice. Conclusions— Upregulation of VEGFR-2 abundance at the protein level contributes in part to increased angiogenesis in VEGFR-1–deficient mice.

Diffuse large cell lymphomas are aggressive tumors of B-cell origin. In some cases they arise from low-grade follicular lymphomas carrying the t(14;18) translocation, an event that leads to the overexpression of the BCL-2 gene product. More frequently, however, they lack the t(14;18) translocation. Rearrangements of the c-MYC proto-oncogene and mutations of the p53 tumor suppressor gene have also been documented in these lymphomas. This study examines the extent to which alterations in the BCL-2, c-MYC, and p53 genes co-exist within individual lymphomas. Eight diffuse large cell lymphoma cell lines and 11 diffuse large cell lymphoma tumors were assessed for genetic alterations in these three genes. Our results indicate that there is a heterogeneity in the oncogene/suppressor gene profile among diffuse large cell lymphomas. Two cell lines and one tumor carried alterations in all three genes, one cell line carried alterations of c-MYC and p53, and one primary tumor and one cell line carried p53 mutations and the t(14;18). Single alterations of BCL-2 and p53 were also observed. Another cell line had no alterations in any of these genes. The heterogeneity indicates that varied mechanisms may be involved in the generation of diffuse large cell lymphomas.

To investigate the clinical features and perioperational managements of craniophayngiomas located in posterior fossa.Nine patients with craniopharyngioma situated in posterior fossa were included in the study. The clinical manifestations, neuroimage features, operational treatment, and perioperational managments were retrospectively analyzed. RESULTS; All tumors associated with big or huge volume, arised from sellar/suprasellar region and extended into posterior fossa. Tumors showed cystic lesions in 2 cases and cystic-solid lesions in 7 cases. Headache was the most common symptoms (6/9), followed by cranial nerve deficit (4/9) and endocrine dysfunction(3/9). The supra- and infra-tentorial approaches were the optimal approaches for removal these tumors (7/9). Cranial nerves deficit was the most common complication in perioperative period. No perioperational death occured, most of the patients showed good recovery during the fellow-up period.Craniophayngiomas in posterior fossa shows different clinical manifestations, radiological features, surgical complications to the tumor in sellar/suprasellar region.

Retinopathy of prematurity is a major side effect of oxygen therapy for preterm infants, and is a leading cause of blindness in children. To date, it remains unclear whether the initial microvascular obliteration is triggered by degradation of hypoxia inducible factor (HIF) α proteins or by other mechanisms such as oxidative stress. Here we show that prolyl hydroxylase domain protein 2 (PHD2), an enzyme mostly responsible for oxygen-induced degradation of HIF-α proteins, plays a major role in oxygen-induced retinopathy in mice. In neonatal mice expressing normal amounts of PHD2, exposure to 75% oxygen caused significant degradation of retinal HIF-α proteins, accompanied by massive losses of retinal microvessels. PHD2 deficiency significantly stabilized HIF-1α, and to some extent HIF-2α, in neonatal retinal tissues, and protected retinal microvessels from oxygen-induced obliteration. After hyperoxia-treated neonatal mice were returned to ambient room air, retinal vasculature in PHD2-deficient mice remained mostly intact and showed very little neoangiogenesis. These findings demonstrate a close association between PHD2-dependent HIF-α degradation and oxygen-induced retinal microvascular obliteration, and imply that PHD2 may be a promising therapeutic target to prevent oxygen-induced retinopathy.

PHD1, PHD2, and PHD3 are prolyl hydroxylase domain proteins that regulate the stability of hypoxia-inducible factor alpha subunits (HIF-alpha). To determine the roles of individual PHDs during mouse development, we disrupted all three Phd genes and found that Phd2(-/-) embryos died between embryonic days 12.5 and 14.5 whereas Phd1(-/-) or Phd3(-/-) mice were apparently normal. In Phd2(-/-) mice, severe placental and heart defects preceded embryonic death. Placental defects included significantly reduced labyrinthine branching morphogenesis, widespread penetration of the labyrinth by spongiotrophoblasts, and abnormal distribution of trophoblast giant cells. The expression of several trophoblast markers was also altered, including an increase in the spongiotrophoblast marker Mash2 and decreases in the labyrinthine markers Tfeb and Gcm1. In the heart, trabeculae were poorly developed, the myocardium was remarkably thinner, and interventricular septum was incompletely formed. Surprisingly, while there were significant global increases in HIF-alpha protein levels in the placenta and the embryo proper, there was no specific HIF-alpha increase in the heart. Taken together, these data indicate that among all three PHD proteins, PHD2 is uniquely essential during mouse embryogenesis.

Background— The development of the vascular system is a complex process that involves communications among multiple cell types. As such, it is important to understand whether a specific gene regulates vascular development directly from within the vascular system or indirectly from nonvascular cells. Hypoxia-inducible factor-2α (Hif-2α, or endothelial PAS protein-1 [EPAS-1]) is required for vascular development in mice, but it is not clear whether its requirement resides directly in endothelial cells. Methods and Results— To address this issue, we expressed Hif-2 α cDNA in the vascular endothelium of Hif-2 α −/− embryos by an embryonic stem (ES) cell–mediated transgenic approach and assessed whether endothelium-specific reexpression of Hif-2 α could rescue vascular development. Here we report that although ES cell–derived Hif-2 α −/− embryos developed severe vascular defects by embryonic day (E) 11.5 and died in utero before E12.5, endothelium-specific expression of Hif-2 α cDNA restored normal vascular development at all stages examined (up to E14.5) and allowed Hif-2 α −/− embryos to survive at a frequency comparable to that of Hif-2 α +/− embryos. Furthermore, we found that Tie-2 expression was significantly reduced in Hif-2 α −/− mutants but was restored by Hif-2 α cDNA expression. Conclusions— These data demonstrate an intrinsic requirement for Hif-2α by endothelial cells and imply that hypoxia may control endothelial functions directly via Hif-2α–regulated Tie-2 expression.

This study attempts to address an important clinical issue by identifying potential candidates of VEGF signaling through Flt-1 receptor that trigger angiogenic signal under ischemic stress. To determine the significance of VEGF-Flt-1 (VEGFR1) signaling in ischemic preconditioned (PC) myocardium, we used heterozygous Flt-1 knockout (KO) mice to dissect the pathway and identify candidate genes involved in VEGF signaling. DNA microarrays were employed to detect, characterize and distinguish altered myocardial gene expression by comparing between wild type (WT) CD-1 and heterozygous Flt-1 KO mice when exposed to ischemia (30 min) and reperfusion (2 h). Moreover, KO mice demonstrated reduced beneficial effects of PC when compared to the WT with PC. In the KO and WT mice, the % recovery of the left ventricular developed pressure and the maximum first derivative of the developed pressure after ischemia/reperfusion without PC were similar. However, when animals were subjected to PC, the left ventricular functional recovery throughout the reperfusion period was significantly lower in KO mice than in WT mice. These results indicate for the first time that in the heterozygous Flt-1 KO mice, PC is not as effective as that found in WT. This observation may be due to downregulation of several important genes such as growth-regulated oncogene 1 (Gro1), heat shock proteins (HSP), I kappa B kinase β (IKKβ), colony-stimulating factor-1 (CSF-1) and annexin A7, suggesting the importance of VEGF-Flt-1 receptor signaling during PC.

Mouse embryogenesis is dose sensitive to vascular endothelial growth factor-A (VEGF-A), and mouse embryos partially deficient in VEGF-A die in utero because of severe vascular defects. In this study, we investigate the possible causes that underlie this phenomenon. Although the development of vascular defects in VEGF-A-deficient embryos seems to suggest that endothelial differentiation depends on the presence of a sufficient level of VEGF-A, we were surprised to find that endothelial differentiation per se is insensitive to a significant loss of VEGF-A activity. Instead, the development of the multipotent mesenchymal cells, from which endothelial progenitors arise in the yolk sac, is most highly dependent on VEGF-A. As a result of VEGF-A deficiency, dramatically fewer multipotent mesenchymal cells are generated in the prospective yolk sac. However, among the small number of mesenchymal cells that do enter the prospective yolk sac, endothelial differentiation occurs at a normal frequency. In the embryo proper, vasculogenesis is initiated actively in spite of a significant VEGF-A deficiency, but the subsequent steps of vascular development are defective. We conclude that a full-level VEGF-A activity is not critical for endothelial specification but is important for two distinct processes before and after endothelial specification: the development of the yolk sac mesenchyme and angiogenic sprouting of blood vessels.

We have isolated the Xenopus homologue of Muscle LIM protein (MLP, CRP3) and examined its expression during early embryonic development. MLP is only expressed in the differentiated heart during early development and is expressed in a subset of other striated muscles during later stages. There is no MLP expression during primary myogenesis in the somites, although it is found in adult skeletal muscle.

Here we investigate the role of hypoxia inducible factor (HIF)-2α in coordinating the development of retinal astrocytic and vascular networks. Three Cre mouse lines were used to disrupt floxed Hif-2α, including Rosa26(CreERT2), Tie2(Cre), and GFAP(Cre). Global Hif-2α disruption by Rosa26(CreERT2) led to reduced astrocytic and vascular development in neonatal retinas, whereas endothelial disruption by Tie2(Cre) had no apparent effects. Hif-2α deletion in astrocyte progenitors by GFAP(Cre) significantly interfered with the development of astrocytic networks, which failed to reach the retinal periphery and were incapable of supporting vascular development. Perplexingly, the abundance of strongly GFAP(+) mature astrocytes transiently increased at P0 before they began to lag behind the normal controls by P3. Pax2(+) and PDGFRα(+) astrocytic progenitors and immature astrocytes were dramatically diminished at all stages examined. Despite decreased number of astrocyte progenitors, their proliferation index or apoptosis was not altered. The above data can be reconciled by proposing that HIF-2α is required for maintaining the supply of astrocyte progenitors by slowing down their differentiation into non-proliferative mature astrocytes. HIF-2α deficiency in astrocyte progenitors may accelerate their differentiation into astrocytes, a change which greatly interferes with the replenishment of astrocyte progenitors due to insufficient time for proliferation. Rapidly declining progenitor supply may lead to premature cessation of astrocyte development. Given that HIF-2α protein undergoes oxygen dependent degradation, an interesting possibility is that retinal blood vessels may regulate astrocyte differentiation through their oxygen delivery function. While our findings support the consensus that retinal astrocytic template guides vascular development, they also raise the possibility that astrocytic and vascular networks may mutually regulate each other's development, mediated at least in part by HIF-2α.

We have isolated the Xenopus homologue of cardiac myosin-binding protein C ( cMyBP-C) and describe its expression during early embryogenesis. cMyBP-C is expressed in both somites and heart at the time these tissues differentiate. Expression in the somites declines in older tadpoles. There is a high degree of conservation in residues where mutations causing hypertrophic cardiomyopathy have been identified in humans.

Prolyl hydroxylase domain (PHD) proteins catalyze oxygen-dependent prolyl hydroxylation of hypoxia-inducible factor 1α and 2α, tagging them for pVHL-dependent polyubiquitination and proteasomal degradation. In this study, albumin Cre (Alb(Cre))-mediated, hepatocyte-specific triple disruption of Phd1, Phd2, and Phd3 (Phd(1/2/3)hKO) promoted liver erythropoietin (EPO) expression 1246-fold, whereas renal EPO was down-regulated to 6.7% of normal levels. In Phd(1/2/3)hKO mice, hematocrit levels reached 82.4%, accompanied by severe vascular malformation and steatosis in the liver. In mice double-deficient for hepatic PHD2 and PHD3 (Phd(2/3)hKO), liver EPO increase and renal EPO loss both occurred but were much less dramatic than in Phd(1/2/3)hKO mice. Hematocrit levels, vascular organization, and liver lipid contents all appeared normal in Phd(2/3)hKO mice. In a chronic renal failure model, Phd(2/3)hKO mice maintained normal hematocrit levels throughout the 8-week time course, whereas floxed controls developed severe anemia. Maintenance of normal hematocrit levels in Phd(2/3)hKO mice was accomplished by sensitized induction of liver EPO expression. Consistent with such a mechanism, liver HIF-2α accumulated to higher levels in Phd(2/3)hKO mice in response to conditions causing modest systemic hypoxia. Besides promoting erythropoiesis, EPO is also known to modulate retinal vascular integrity and neovascularization. In Phd(1/2/3)hKO mice, however, neonatal retinas remained sensitive to oxygen-induced retinopathy, suggesting that local EPO may be more important than hepatic and/or renal EPO in mediating protective effects in the retina.