Levels Of Hypoxia-inducible Factor-1alpha Research Articles

Linking renal hypoxia and oxidative stress in chronic kidney disease: Based on clinical subjects and animal models.

This study aims to explore the relationships between renal function, hypoxia, and oxidative stress in chronic kidney disease (CKD). Seventy-six non-dialysis patients with CKD stages 1-5 and eight healthy subjects were included in the clinical research. They were divided into three groups: healthy subjects, CKD stages 1-3, and CKD stages 4-5. In the animal study, 16 rat models of CKD were established through 5/6 renal ablation/infarction (A/I) surgery, and 8 normal rats were split into 3 groups: Sham, CKD, and losartan groups. Blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) was used to measure cortical and medullary T2* values (COT2* and MET2*) in all subjects and rats to evaluate renal oxygenation. Biochemical indicators were used to assess renal function and antioxidant capacity. Furthermore, the effects of losartan on renal fibrosis, hypoxia, and oxidative stress were examined using immunoblotting, colorimetric, and fluorometric assays. The results demonstrated significant positive associations between COT2* and MET2* with estimated glomerular filtration rate (eGFR). Patients with CKD stages 4-5 showed significantly lower serum superoxide dismutase (SOD) levels, which also had positive correlations with eGFR, COT2*, and MET2*. Furthermore, losartan treatment resulted in improved renal function and fibrosis, leading to increased levels of COT2*, MET2*, and SOD levels in 5/6 A/I rats. This was accompanied by reduced levels of hypoxia-inducible factor-1 alpha (HIF-1α) and malondialdehyde. Furthermore, losartan restored the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), and suppressed the expression of Kelch-like ECH-associated protein 1 (Keap1) in 5/6 A/I kidneys. The study indicates that decline in renal oxygenation and antioxidant capacity is associated with the severity of renal failure in CKD. Losartan can potentially alleviate renal hypoxia and oxidative stress in the treatment of CKD via Keap1-Nrf2/HO-1 pathway.

Exosomes secreted by ST3GAL5high cancer cells promote peritoneal dissemination by establishing a premetastatic microenvironment.

Peritoneal dissemination of cancer affects patient survival. The behavior of peritoneal mesothelial cells (PMCs) and immune cells influences the establishment of a microenvironment that promotes cancer cell metastasis in the peritoneum. Here, we investigated the roles of lactosylceramide alpha-2,3-sialyltransferase (ST3G5; also known as ST3GAL5 and GM3 synthase) in the exosome-mediated premetastatic niche in peritoneal milky spots (MSs). Exosomes secreted from ST3G5high cancer cells (ST3G5high -cExos) were found to contain high levels of hypoxia-inducible factor 1-alpha (HIF1α) and accumulated in MSs via uptake in macrophages (MΦs) owing to increased expression of sialic acid-binding Ig-like lectin 1 (CD169; also known as SIGLEC1). ST3G5high -cExos induced pro-inflammatory cytokines and glucose metabolic changes in MΦs, and the interaction of these MΦs with PMCs promoted mesothelial-mesenchymal transition (MMT) in PMCs, thereby generating αSMA+ myofibroblasts. ST3G5high -cExos also increased the expression of immune checkpoint molecules and T-cell exhaustion in MSs, which accelerated metastasis to the omentum. These events were prevented following ST3G5 depletion in cancer cells. Mechanistically, ST3G5high -cExos upregulated chemokines, including CC-chemokine ligand 5 (CCL5), in recipient MΦs and dendritic cells (DCs), which induced MMT and immunosuppression via activation of signal transducer and activator of transcription 3 (STAT3). Maraviroc, a C-C chemokine receptor type 5 (CCR5) antagonist, prevented ST3G5high -cExo-mediated MMT, T-cell suppression, and metastasis in MSs. Our results suggest ST3G5 as a suitable therapeutic target for preventing cExo-mediated peritoneal dissemination.

Promyelocytic leukemia protein regulates angiogenesis and epithelial-mesenchymal transition to limit metastasis in MDA-MB-231 breast cancer cells.

Promyelocytic leukemia protein (PML) modulates diverse cell functions that contribute to both tumor-suppressor and pro-oncogenic effects, depending on the cellular context. We show here that PML knockdown (KD) in MDA-MB-231, but not MCF7, breast cancer cells, prolonged stem-cell-like survival, and increased cell proliferation and migration, which is in line with gene-enrichment results from their RNA sequencing analysis. Of note, increased migration was accompanied by higher levels of the epithelial-mesenchymal transition (EMT) regulator Twist-related protein 2 (TWIST2). We showed here that PML binds to TWIST2 via its basic helix-loop-helix (bHLH) region and functionally interferes with suppression of the epithelial target of TWIST2, CD24. In addition, PML ablation in MDA-MB-231 cells led to higher protein levels of hypoxia-inducible factor 1-alpha (HIF1a), resulting in a higher cell hypoxic response. Functionally, PML directly suppressed induction of the HIF1a target gene vascular endothelial growth factor A (VEGFa). In line with these results, tumor xenografts of MDA-MB-231 PML-KD cells had enhanced aggressive properties, including higher microvessel density, faster local growth and higher metastatic ability, with a preference for lung. Collectively, PML suppresses the cancer aggressive behavior by multiple mechanisms that impede both the HIF-hypoxia-angiogenic and EMT pathways.

Biomimetic gene editing system for precise tumor cell reprogramming and augmented tumor therapy.

The abnormal level of hypoxia-inducible factor-1 alpha (HIF-1α) is closely related to cancer metastasis and treatment resistance. CRISPR-Cas9-based gene editing technology has sparked profound hope to solve this issue by precise gene disruption, although the in vivo application remains hindered by the lack of a safe and efficient delivery strategy. Herein, we developed a cell membrane biomimetic core-shell system for light-controllable, precise gene editing. The inner core of the system comprises protamine for CRISPR-Cas9/sgRNA plasmid (pCas9) loading and calcium ions for efficient pCas9 transfection. The shell of the system is camouflaged by a cell membrane and modified with AS1411 aptamers for tumor targeting and photosensitizers to induce lysosomal escape and pCas9 release through reactive oxygen species production, thereby producing light-controllable enhanced gene editing. Neoplastic H1299 cells were reprogrammed using the biomimetic gene editing system upon laser irradiation with reduced VEGF and Vimentin expression, leading to enhanced antimetastatic effects. Genetic disruption of HIF-1α augmented the in vivo chemotherapeutic efficacy of paclitaxel. Our approach of using a membrane-camouflaged system combined with light augmentation provides a potential solution for the in vivo delivery of CRISPR-Cas9 as well as a feasible strategy for cancer therapy.

PS-B12-4: SOLUBLE (PRO)RENIN RECEPTOR LEVEL INCREASED IN A RAT MODEL OF REDUCED UTERINE PERFUSION PRESSURE

Objective: The (pro)renin receptor [(P)RR)] is a multifunctional protein with roles in angiotensin II-dependent and -independent intracellular cell signaling and as an adaptor protein between the Wnt receptor complex and vacuolar proton-translocating adenosine triphosphatase. The (P)RR is cleaved from the full length (P)RR to generate soluble (P)RR [s(P)RR], reflecting the status of the tissue activity of the (P)RR. We have shown that maternal blood s(P)RR concentrations in early pregnancy are associated with increased blood pressure in late pregnancy, while higher levels of s(P)RR in cord blood in babies are at lower risk of low birth weight. We have also reported that intracellular s(P)RR is increased by hypoxia and interacts with pyruvate dehydrogenase β; subunit (PDHB) to stabilize PDHB protein and pyruvate dehydrogenase (PDH) activity in trophoblast cells, leading to our hypothesis that (P)RR may help maintain oxidative metabolism and efficient energy production during placental ischemia. In this in vivo study, we investigated effects of reduced uterine perfusion pressure (RUPP) on PDH activity and s(P)RR levels in rats. Design and method: RUPP was induced by placing sliver clips around the aorta above the iliac bifurcation and the bilateral uterine arcades in pregnant Sprague Dawley rats on gestational day 14 (RUPP rats). Weights of placentas and infants were measured on gestational day 21. mRNA expressions of (P)RR, hypoxia-inducible factor 1-alpha (HIF1a), and PDHB, and protein levels of HIF1a, (P)RR, s(P)RR, PDHB, lactate, and pyruvate, and activity of PDH in placentas were measured on gestational day 21. Result: Weight of placentas and infants were significantly decreased in RUPP rats when compared with those of sham rats. mRNA and protein levels of HIF1a were significantly higher in RUPP rats than in control sham rats, indicating that ischemia was actually induced by RUPP. mRNA levels of (P)RR and PDHB were not significantly different between the groups. The protein level of (P)RR was not significantly different between the groups while s(P)RR protein level was significantly higher in RUPP rats than in controls. Concentrations of lactate or pyruvate and PDH activity were not significantly different between the groups. Conclusion: PDH activity was not decreased even under the condition of placental ischemia. s(P)RR but not full length (P)RR was increased by placental ischemia. These data suggested that s(P)RR might be increased by placental ischemia to maintain mitochondrial oxidative metabolism in rats.

Differential Expression of HIF1A, EPAS1, and VEGF Genes in Benign and Malignant Ovarian Neoplasia.

Simple SummaryOvarian cancer (OC) has the highest mortality rate of all gynecological malignancies. Moreover, at the time of the first clinical manifestation, most patients have an advanced stage of the disease. Our study examined differences in mRNA levels of hypoxia-inducible factor 1-alpha (HIF1A); endothelial PAS domain protein 1, also known as hypoxia-inducible factor 2-alpha (HIF2A/EPAS1); and vascular endothelial growth factor A (VEGFA) between cancerous tissue, benign hyperplastic changes in the ovary, and normal tissue. We found that gene expression changes were visible not only in the case-control study, but also along with changes in severity. We observed disturbances in the expression levels of interdependent genes. Our findings suggest that mutual association in the expression of both HIF1A and HIF2A/EPAS1 with VEGFA has prognostic importance for patients with OC. Our observations may help identify patients for clinical trials aimed at inhibiting the hypoxia-induced neovascularization-dependent pathways.Ovarian cancer (OC) has the highest mortality rate of all gynecological malignancies. Moreover, at the time of the first clinical manifestation, most patients have an advanced stage of the disease. Our study examined differences in mRNA levels of hypoxia-inducible factor 1-alpha (HIF1A); endothelial PAS domain protein 1, also known as hypoxia-inducible factor 2-alpha (HIF2A/EPAS1); and vascular endothelial growth factor A (VEGFA) between cancerous tissue, benign hyperplastic changes in the ovary, and normal tissue. Our cohorts consisted of 52 patients diagnosed with OC (n = 55), benign non-cancerous changes (n = 21), and normal tissue samples (n = 38). The mRNA expression level was evaluated using RT-qPCR. We found that gene expression changes were visible not only in the case-control study, but also along with changes in severity. Additionally, the gene expression was differentiated in age, BMI, menopausal status, and the number of comorbidy-related groups. Furthermore, our findings demonstrate that analyzing the correlation between genes is essential. In a case-to-case and case-to-control study, we observed disturbances in the expression levels of interdependent genes. Our findings suggest that mutual association in the expression of both HIF1A and HIF2A/EPAS1 with VEGFA has prognostic importance for patients with OC. Our observations may help identify patients for clinical trials aimed at inhibiting the hypoxia-induced neovascularization-dependent pathways.

Effect of Transcatheter Arterial Chemoembolization Combined with Radiofrequency Ablation on Liver Function and Immune Function in Patients with Hepatocellular Carcinoma.

Objectives To investigate the effects of transcatheter arterial chemoembolization (TACE) combined with radiofrequency ablation (RFA) on liver function and immune function in patients with hepatocellular carcinoma (HCC). Methods From December 2016 to January 2019, patients with primary liver cancer who could not be operated on were selected as the study subjects. 170 patients were randomly divided into two groups. The control group was treated with transcatheter arterial chemoembolization (n = 85). The patients in the observation group were treated with transcatheter arterial chemoembolization combined with radiofrequency ablation (n = 85). The clinical effects of the two groups were analyzed. The changes of liver function and immune function were detected by automatic biochemical analyzer before and after treatment. The changes of hypoxia inducible factor-1 (HIF1) alpha and vascular endothelial growth factor (VEGF) levels before and after treatment were analyzed by enzyme-linked immunosorbent assay (ELISA). Results The total effective rate in the observation group was significantly higher than that in the control group (P < 0.05). After treatment, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), CD8+, HIF1 alpha, and VEGF decreased significantly (P < 0.05), while levels of total bilirubin, direct bilirubin, indirect bilirubin, CD3+, CD4+, and CD4+/CD8+ increased significantly (P < 0.05). The changes of the above indexes in the observation group were more significant than those in the control group (P < 0.05). Conclusion Hepatic arterial chemoembolization combined with radiofrequency ablation has a significant effect on liver function and immune function in patients with liver cancer, which may be related to the abnormal levels of HIF1α and vascular endothelial growth factor.

A Novel Laser-Based Zebrafish Model for Studying Traumatic Brain Injury and Its Molecular Targets.

Traumatic brain injury (TBI) is a major public health problem. Here, we developed a novel model of non-invasive TBI induced by laser irradiation in the telencephalon of adult zebrafish (Danio rerio) and assessed their behavior and neuromorphology to validate the model and evaluate potential targets for neuroreparative treatment. Overall, TBI induced hypolocomotion and anxiety-like behavior in the novel tank test, strikingly recapitulating responses in mammalian TBI models, hence supporting the face validity of our model. NeuN-positive cell staining was markedly reduced one day, but not seven days, after TBI, suggesting increased neuronal damage immediately after the injury, and its fast recovery. The brain-derived neurotrophic factor (Bdnf) level in the brain dropped immediately after the trauma, but fully recovered seven days later. A marker of microglial activation, Iba1, was elevated in the TBI brain, albeit decreasing from Day 3. The levels of hypoxia-inducible factor 1-alpha (Hif1a) increased 30 min after the injury, and recovered by Day 7, further supporting the construct validity of the model. Collectively, these findings suggest that our model of laser-induced brain injury in zebrafish reproduces mild TBI and can be a useful tool for TBI research and preclinical neuroprotective drug screening.

Cardiac rehabilitation may influence leptin and VEGF A crosstalk in patients after acute coronary syndrome

Leptin, a well-proven cardiovascular risk factor, influences vascular endothelial growth factor A (VEGF A) synthesis via hypoxia-inducible factor 1 alpha (HIF-1A), nuclear factor kappa-light-chain-enhancer of activated B cells (NfkB) and NILCO (Notch, interleukin 1 [IL1] and leptin cross-talk outcome) pathways. This study aimed to investigate the influence of cardiac rehabilitation (CR) on HIF-1A, NfkB and NILCO dependent leptin and VEGF A cross-talk in patients after acute coronary syndrome (ACS). Fifty post-ACS patients underwent a 2-week CR programme (study group S) and were compared to 50 post-ACS subjects who did not undergo CR (control group K). In group S, at baseline and at completion and in group K once, anthropometric, body composition, blood pressure and heart rate measurements were taken and blood sampling was performed. Serum levels of leptin, VEGF A, VEGF receptor 2 (VEGF R2), HIF-1A, NfkB, interleukin 1-alpha (IL1-alpha) and Notch 1 were determined. In group S, serum VEGF A levels increased while leptin, HIF-1A and VEGF R2 levels decreased and completion but not baseline serum leptin correlated positively with serum VEGF A. Also, serum completion VEGF A correlated positively with NfkB and HIF-1A in group S. Correlation analysis in group S confirmed the significant role of the NILCO pathway in the regulation of VEGF A serum levels mediated by HIF-1A and NfkB. CR may induce the predomination of the NILCO pathway interacting with HIF-1A and NfkB over leptin canonical and non-canonical signalling pathways in the leptin influence on VEGF A in post-ACS patients.Trial registration: ClinicalTrials.gov ID: NCT03935438. The CARDIO-REH randomised study.

Fenofibrate Improves Cognitive Impairment Induced by High-Fat High-Fructose Diet: A Possible Role of Irisin and Heat Shock Proteins.

A high-fat, high-fructose diet (HFFD) impairs cognitive functions and increases susceptibility to neurodegenerative disorders. Irisin and heat shock protein 70 (HSP70) are well known for their role in neuroprotection. The possible neuroprotective effects of fenofibrate on HFFD-induced cognitive dysfunction and the involvement of irisin and HSP70 in these effects were investigated in this study. Rats were divided into normal control, HFFD, dimethylsulfoxide+HFFD, and fenofibrate+HFFD groups. At the end of the experiment, fenofibrate treatment restored hippocampus histological characteristics to almost normal and improved HFFD-induced cognitive deficit. It reduced body weight gain and had hypolipidemic effects by significantly lowering total cholesterol, triglycerides, and low-density lipoprotein cholesterol levels while increasing high-density lipoprotein cholesterol levels. It has antioxidant and anti-inflammatory effects as it significantly reduced the hippocampal malondialdehyde, interleukin-6, and tumor necrosis factor-alpha levels, while significantly increasing the reduced glutathione level. It prevented HFFD-induced hypoxia by significantly lowering hippocampal vascular endothelial growth factor and hypoxia-inducible factor-1 alpha levels. It significantly activated the hippocampal peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α)/irisin/brain-derived neurotrophic factor pathway. It significantly increased hippocampal HSP70 while decreasing the HSP90 levels. It enhanced synaptic plasticity by significantly upregulating the hippocampal relative GluR1 gene expression. Furthermore, hippocampal irisin levels in the HFFD group were found to be positively correlated with cognitive function, hippocampal HSP70, and relative GluR1 gene expression levels, while negatively correlated with hippocampal HSP90 and HIF1α levels. Therefore, fenofibrate may be used as a potential medication to treat HFFD-induced neurodegenerative disorders.

Leptin and vascular endothelial growth factor A: a cross-talk in obese women with gestational diabetes and with diabetes in pregnancy - a cohort study.

Vascular endothelial growth factor A (VEGF A) synthesis is intensified by leptin in: hypoxia-inducible factor 1 alpha (HIF-1A) and nuclear factor kappa-light-chain-enhancer of activated B cells (NfκB)-dependent manners. The study aimed to investigate the association between leptin and VEGF A serum levels in obese women with hyperglycaemia in the third trimester of pregnancy. Sixty obese pregnant women with hyperglycaemia were divided into groups according to body mass index (BMI): group 1: BMI 30.0-34.9 kg/m2; group 2: BMI 35.0-39.9 kg/m2; group 3: BMI ≥40 kg/m2. On the enrolment visit, waist circumference, body mass and height were measured. At visit 1 (V1; gestational week (GW) 28-32) and visit 2 (V2; GW 36-38), anthropometric, blood pressure and heart rate measurements, and blood sample collection were performed. Blood levels of leptin, VEGF A, VEGF receptor 2, HIF-1A, NfκB, interleukin 1 alpha, protein delta homolog 1, nitric oxide and glycated haemoglobin were determined. To analyse the predictors of the biochemical parametres involved in leptin and VEGF A cross-talk, multivariate logistic regression was implemented. Positive correlations between serum levels of leptin and VEGF A were found. Serum level of HIF-1A at V1 was a predictor for the highest quartile of the serum levels of VEGF A at V1 and V2. Leptin serum level at V1 was a predictor for the highest quartile of HIF-1A serum concentration at V2. In group 3 HIF-1A level was higher at V2 compared to V1. We conclude that in obese women with hyperglycaemia in the third trimester of pregnancy there is a significant positive influence of serum leptin on VEGF A synthesis and serum level and HIF-1A seems to play more important role in leptin and VEGF A cross-talk than NfκB.

Implantation of Hypoxia-Induced Mesenchymal Stem Cell Advances Therapeutic Angiogenesis.

Hypoxia preconditioning enhances the paracrine abilities of mesenchymal stem cells (MSCs) for vascular regeneration and tissue healing. Implantation of hypoxia-induced mesenchymal stem cells (hi-MSCs) may further improve limb perfusion in a murine model of hindlimb ischemia. This study is aimed at determining whether implantation of hi-MSCs is an effective modality for improving outcomes of treatment of ischemic artery diseases. We evaluated the effects of human bone marrow-derived MSC implantation on limb blood flow in an ischemic hindlimb model. hi-MSCs were prepared by cell culture under 1% oxygen for 24 hours prior to implantation. A total of 1 × 105 MSCs and hi-MSCs and phosphate-buffered saline (PBS) were intramuscularly implanted into ischemic muscles at 36 hours after surgery. Restoration of blood flow and muscle perfusion was evaluated by laser Doppler perfusion imaging. Blood perfusion recovery, enhanced vessel densities, and improvement of function of the ischemia limb were significantly greater in the hi-MSC group than in the MSC or PBS group. Immunochemistry revealed that hi-MSCs had higher expression levels of hypoxia-inducible factor-1 alpha and vascular endothelial growth factor A than those in MSCs. In addition, an endothelial cell-inducing medium showed high expression levels of vascular endothelial growth factor, platelet endothelial cell adhesion molecule-1, and von Willebrand factor in hi-MSCs compared to those in MSCs. These findings suggest that pretreatment of MSCs with a hypoxia condition and implantation of hi-MSCs advances neovascularization capability with enhanced therapeutic angiogenic effects in a murine hindlimb ischemia model.

Anti-hypoxia effects of ginseng (Panax Ginseng C A Meyer) oligopeptides in mice

Purpose: To study the anti-hypoxia effects of ginseng oligopeptides (GOPs) in mice.&#x0D; Methods: Mice were randomly assigned to six groups: vehicle control group, whey protein-fed group (0.30 g/kg body weight, BW), and four groups given GOP at doses of 0.075, 0.150, 0.300, 0.600 g/kg BW. All treatments were administered via gavage once a day for a total of 30 days.&#x0D; Results: GOPs significantly extended survival times under normobaric hypoxia, sodium nitrite toxicosis and acute cerebral ischemia. Moreover, GOPs enhanced the levels of RBC, Hb and Hct; decreased brain malonaldehyde (MDA) and lactate contents, enhanced brain lactate dehydrogenase (LDH) activity, and upregulated the mRNA expression levels of hypoxia-inducible factor 1alpha (HIF1α) and vascular endothelial growth factor (VEGF).&#x0D; Conclusion: GOPs exert anti-hypoxia effects via mechanisms which may involve improvement of oxygen-carrying capacity of blood and oxygen utilization, reduction of lipid peroxidation-associated lesions, enhancement of brain capacity to buffer against lactic acidosis, promotion of angiogenesis, and regulation of response to hypoxia.

Visualization of tumor heterogeneity and prediction of isocitrate dehydrogenase mutation status for human gliomas using multiparametric physiologic and metabolic MRI

This study aimed to differentiate isocitrate dehydrogenase (IDH) mutation status with the voxel-wise clustering method of multiparametric magnetic resonance imaging (MRI) and to discover biological underpinnings of the clusters. A total of 69 patients with treatment-naïve diffuse glioma were scanned with pH-sensitive amine chemical exchange saturation transfer MRI, diffusion-weighted imaging, fluid-attenuated inversion recovery, and contrast-enhanced T1-weighted imaging at 3 T. An unsupervised two-level clustering approach was used for feature extraction from acquired images. The logarithmic ratio of the labels in each class within tumor regions was applied to a support vector machine to differentiate IDH status. The highest performance to predict IDH mutation status was found for 10-class clustering, with a mean area under the curve, accuracy, sensitivity, and specificity of 0.94, 0.91, 0.90, and 0.91, respectively. Targeted biopsies revealed that the tissues with labels 7–10 showed high expression levels of hypoxia-inducible factor 1-alpha, glucose transporter 3, and hexokinase 2, which are typical of IDH wild-type glioma, whereas those with labels 1 showed low expression of these proteins. In conclusion, A machine learning model successfully predicted the IDH mutation status of gliomas, and the resulting clusters properly reflected the metabolic status of the tumors.

NIMG-36. VISUALIZATION OF TUMOR HETEROGENEITY AND PREDICTION OF ISOCITRATE DEHYDROGENASE MUTATION STATUS FOR HUMAN GLIOMAS BY USING MULTIPARAMETRIC PHYSIOLOGIC AND METABOLIC MRI

Abstract Preoperative prediction of isocitrate dehydrogenase mutation status is clinically meaningful, but remains challenging. This study aimed to predict the isocitrate dehydrogenase (IDH) status of gliomas by using the machine learning voxel-wise clustering method of multiparametric physiologic and metabolic magnetic resonance imaging (MRI) and to show the association of the created cluster labels with the glucose metabolism status of the tumors. Sixty-nine patients with diffuse glioma were scanned by pH-sensitive MRI, diffusion-weighted imaging, fluid-attenuated inversion recovery, and contrast-enhanced T1-weighted imaging at 3 T. An unsupervised two-level clustering approach, including the generation of a self-organizing map followed by the K-means clustering, was used for voxel-wise feature extraction from the acquired images. The logarithmic ratio of the labels in each class within tumor regions was applied to a support vector machine to differentiate IDH mutation status. Bootstrapping and leave-one-out cross-validation were used to calculate the area under the curve (AUC) of receiver operating characteristic curves, accuracy, sensitivity, and specificity for evaluating performance. Targeted biopsies were performed for 14 patients to explore the relationship between clustered labels and the expression of key glycolytic proteins determined using immunohistochemistry. The highest prediction performance to differentiate IDH status was found for 10-class clustering, with a mean AUC, accuracy, sensitivity, and specificity of 0.94, 0.91, 0.90, and 0.91, respectively. The tissues with labels 7 + 8 + 9 + 10 showed high expression levels of hypoxia-inducible factor 1-alpha, glucose transporter 3, and hexokinase 2, which are typical of IDH wild-type glioma, whereas those with labels 1 showed low expression of these proteins. Our machine learning model successfully predicted the IDH mutation status of gliomas, and the resulting clusters properly reflected the metabolic status of the tumors.

The prognostic value of hypoxia biomarkers in older patients with chronic heart failure

Abstract Chronic kidney disease (CKD) worsens the prognosis of chronic heart failure (CHF). Hypoxia is the leading link in pathogenesis, especially in older patients with comorbidity. The aim of this study was to investigate the prognostic value of biomarkers of myocardial, renal dysfunction and hypoxia in older patients with CHF. Materials and methods 80 older hypertensive patients with CHF (48 females, mean age 70.7±8.7 years) were examined. CHF was defined according to ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure, 2016. CKD was diagnosed and classified according to the KDIGO guidelines (2012). Serum levels of hypoxia-inducible factor 1-alpha (HIF-1α), endogenous erythropoietin (eEPO), N-terminal propeptide of type B natriuretic hormone (NT-proBNP), cystatin C were assessed. The follow-up period was 12 months; the primary endpoint was total mortality. Results CKD was diagnosed in 49 (61.3%) older patients with CHF. The HIF-1α level was significantly higher in the group of deceased patients than in the survivors (0.08 (IQR 0.06; 0.11) and 0.05 (IQR 0.04; 0.07) ng/ml, p=0.02), as well as the level of NT-proBNP (1126.3 (IQR 551.8; 2750.0) and 164.4 (IQR 135.5; 1100.9) pg/ml, p&amp;lt;0.0001), eEPO (16.92 (ICR 5.43; 64.57) and 5.36 (IQR 1.65; 8.85) mIU/ml, p&amp;lt;0.0001), cystatin C (1.49 (ICR 0.86; 2.13) and 0.99 (IQR 0.82; 1.32) Mg/l, p=0.0005). Cox regression analysis adjusted for sex, age and comorbidity (χ2=36.8, p&amp;lt;0.0001) showed that endogenous erythropoietin, independently of other factors and biomarkers, determined the prognosis of annual mortality in patients with chronic heart failure (HR 3.27 (95% CI 1.08–9.91, p=0.03); χ2=30.7, p=0.0002). When constructing classification trees, in older patients with CHF in the presence of eEPO less than 16.19 mIU/ml NT-proBNP more than 232.5 pg/ml is an unfavorable factor (in patients with NT-proBNP &amp;lt;232.5 pg/ml the risk decreased to 0) (for model: sensitivity – 57.1%; specificity – 92.3% (AUC=0.87); p=0.0015). Conclusions The level of eEPO in older patients with CHF has an independent and closer relationship with the annual mortality of patients than the NT-proBNP – currently accepted biomarker of the severity and prognosis of CHF. Funding Acknowledgement Type of funding sources: None.

COX2 Enhances Neovascularization of Inflammatory Tenocytes Through the HIF-1α/VEGFA/PDGFB Pathway.

Tendon injuries are among the most challenging in orthopedics. During the early tendon repair, new blood vessel formation is necessary. However, excessive angiogenesis also exacerbates scar formation, leading to pain and dysfunction. A significantly worse outcome was associated with higher expression levels of hypoxia-inducible factor-1 alpha (HIF-1α), and its transcriptional targets vascular endothelial growth factor A (VEGFA) and platelet-derived growth factor B (PDGFB), but the underlying molecular mechanisms remain unclear. In this study, lipopolysaccharide (LPS) was used to induce an inflammatory response in tenocytes. LPS increased the tenocytes’ inflammatory factor COX2 expression and activated the HIF-1α/VEGFA/PDGFB pathway. Moreover, the conditioned medium from the tenocytes boosted rat aortic vascular endothelial cell (RAOEC) angiogenesis. Furthermore, Trichostatin A (TSA), an inhibitor of histone deacetylase, was used to treat inflammatory tenocytes. The expression levels of HIF-1α and its transcriptional targets VEGFA and PDGFB decreased, resulting in RAOEC angiogenesis inhibition. Finally, the dual-luciferase reporter gene assay and chromatin immunoprecipitation (ChIP) assay proved that the HIF-1α/PDGFB pathway played a more critical role in tenocyte angiogenesis than the HIF-1α/VEGFA pathway. TSA could alleviate angiogenesis mainly through epigenetic regulation of the HIF-1α/PDGFB pathway. Taken together, TSA might be a promising anti-angiogenesis drug for abnormal angiogenesis, which is induced by tendon injuries.

Serum Hypoxia-Inducible Factor 1alpha Levels Correlate with Outcomes After Intracerebral Hemorrhage.

BackgroundSerum hypoxia-inducible factor 1alpha (HIF-1α) is a key regulator in hypoxic and ischemic brain injury. We determined the relationship between serum HIF-1α levels and long-term prognosis plus severity of intracerebral hemorrhage (ICH).MethodsA total of 97 ICH cases and 97 healthy controls were enrolled. Glasgow Coma Scale (GCS) score and hematoma volume were used to assess hemorrhagic severity. Glasgow Outcome Scale (GOS) score of 1–3 at post-stroke 90 days was defined as a poor outcome.ResultsSerum HIF-1α levels of ICH patients were significantly higher than those of healthy controls (median, 218.8 vs 105.4 pg/mL; P<0.001) and were substantially correlated with GCS score (r=−0.485, P<0.001), hematoma volume (r=0.357, P<0.001) and GOS score (r=−0.436, P<0.001). Serum HIF-1α levels >239.4 pg/mL discriminated patients at risk of 90-day poor outcome with sensitivity of 65.9% and specificity of 79.3% (area under the receiver operating characteristic curve, 0.725; 95% confidence interval, 0.625–0.811; P<0.001). Moreover, serum HIF-1α levels >239.4 pg/mL were independently associated with a poor 90-day outcome (odds ratio, 5.133; 95% confidence interval, 1.117–23.593; P=0.036).ConclusionSerum HIF-1α, in close correlation with hemorrhagic severity and poor 90-day outcome, may serve as a potential prognostic biomarker for ICH.

Modulation of the Dental Pulp Stem Cell Secretory Profile by Hypoxia Induction Using Cobalt Chloride.

The action of stem cells is mediated by their paracrine secretions which comprise the secretory profile. Various approaches can be used to modify the secretory profile of stem cells. Creating a hypoxic environment is one method. The present study aims to demonstrate the influence of CoCl2 in generating hypoxic conditions in a dental pulp stem cell (DPSCs) culture, and the effect of this environment on their secretory profile. DPSCs that were isolated from human permanent teeth were characterized and treated with different concentrations of CoCl2 to assess their viability by an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and proliferation by a cell counting kit (CCK)-8 assay. The gene expression level of hypoxia-inducible factor 1-alpha (HIF-1α) was analyzed by quantitative real time polymerase chain reaction (qRT-PCR) to demonstrate a hypoxic environment. Comparative evaluation of the growth factors and cytokines were done by cytometric bead array. Gene expression levels of transcription factors OCT4 and SOX2 were analyzed by qRT-PCR to understand the effect of CoCl2 on stemness in DPSCs. DPSCs were positive for MSC-specific markers. Doses of CoCl2, up to 20 µM, did not negatively affect cell viability; in low doses (5 µM), it promoted cell survival. Treatment with 10 µM of CoCl2 significantly augmented the genetic expression of HIF-1α. Cells treated with 10 µM of CoCl2 showed changes in the levels of growth factors and cytokines produced. It was very evident that CoCl2 also increased the expression of OCT4 and SOX2, which is the modulation of stemness of DPSCs. A CoCl2 treatment-induced hypoxic environment modulates the secretory profile of DPSCs.

Sirtuin-1 inhibits endothelin-2 expression in human granulosa-lutein cells via hypoxia inducible factor 1 alpha and epigenetic modifications†.

Endothelin-2 (EDN2) expression in granulosa cells was previously shown to be highly dependent on the hypoxic mediator, hypoxia inducible factor 1 alpha (HIF1A). Here, we investigated whether sirtuin-1 (SIRT1), by deacetylating HIF1A and class III histones, modulates EDN2 in human granulosa-lutein cells (hGLCs). We found that HIF1A was markedly suppressed in the presence of resveratrol or a specific SIRT1 activator, SRT2104. In turn, hypoxia reduced SIRT1 levels, implying a mutually inhibitory interaction between hypoxia (HIF1A) and SIRT1. Consistent with reduced HIF1A transcriptional activity, SIRT1 activators, resveratrol, SRT2104, and metformin, each acting via different mechanisms, significantly inhibited EDN2. In support, knockdown of SIRT1 with siRNA markedly elevated EDN2, whereas adding SRT2104 to SIRT1-silenced cells abolished the stimulatory effect of siSIRT1 on EDN2 levels further demonstrating that EDN2 is negatively correlated with SIRT1. Next, we investigated whether SIRT1 can also mediate the repression of the EDN2 promoter via histone modification. Chromatin immunoprecipitation (ChIP) analysis revealed that SIRT1 is indeed bound to the EDN2 promoter and that elevated SIRT1 induced a 40% decrease in the acetylation of histone H3, suggesting that SIRT1 inhibits EDN2 promoter activity by inducing a repressive histone configuration. Importantly, SIRT1 activation, using SRT2104 or resveratrol, decreased the viable numbers of hGLC, and silencing SIRT1 enhanced hGLC viability. This effect may be mediated by reducing HIF1A and EDN2 levels, shown to promote cell survival. Taken together, these findings propose novel, physiologically relevant roles for SIRT1 in downregulating EDN2 and survival of hGLCs.