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Publication
Journal: Nan fang yi ke da xue xue bao = Journal of Southern Medical University
September/28/2020
Abstract
Objective: To explore the effect of mild hypothermia on inflammatory response and angiogenesis in brain tissues of rats with intracerebral hemorrhage (ICH) and its possible mechanism for improving behavioral deficits of the rats After ICH.
Methods: A total of 120 healthy male SD rats were randomly divided into sham operation group, ICH group and mild hypothermia group. Rat models of ICH were established in the latter two groups by stereotactic injection of autogenous blood in the brain, and the rats in the sham operation group received injection of normal saline in the same manner. At 15 min after modeling, the rats in hypothermia group were subjected to mild hypothermia (30-32 ℃) for 8 h followed by rewarming (37-38 ℃); the body temperature was maintained at 37-38 ℃ in the other two groups. At 2, 4, 7, 14 and 21 days after the treatment, Longa scoring, balance beam scoring and Berderson scoring were used to evaluate the behavioral deficits of the rats. Immunohistochemical staining was used to detect the protein expressions of tumor necrosis factor-α (TNF-α) and nuclear factor-κB (NF-κB) in the brain tissue of the rats, and the mRNA expressions of α subunit of hypoxia-inducible factor 1 (HIF1-α) and vascular endothelial growth factor (VEGF) were detected using RT- PCR.
Results: At 2, 4, 7, 14 and 21 days after the treatment, the behavioral scores of the rats were significantly higher in ICH group and mild induced hypothermia group than in the sham operation group (P < 0.05 or 0.01). The protein expressions of TNF-α and NF-κB and mRNA expressions of HIF1-α and VEGF were significantly higher in ICH group and mild hypothermia group than in the sham operation group (P < 0.01). The behavioral scores were significantly lower in mild hypothermia group than in ICH group (P < 0.05), and the protein expressions of TNF-α and NF-κB were lower and the mRNA expressions of HIF1- α and VEGF were higher in mild hypothermia group than in ICH group (P < 0.05 or 0.01).
Conclusions: Mild hypothermia can improve behavioral deficits in rats with ICH possibly by antagonizing brain inflammation and promoting angiogenesis.
Keywords: angiogenesis; animal ethology; inflammatory response; intracerebral hemorrhage; mild hypothermia.
Publication
Journal: Journal of Cellular Physiology
December/5/2018
Abstract
Retinal neovascularization occurs in various ocular disorders including proliferative diabetic retinopathy and secondary neovascular glaucoma, resulting in blindness. This paper aims to investigate the effect of microRNA-141-3p (miR-141-3p) on retinal neovascularization and retinal ganglion cells (RGCs) in glaucoma mice through the Docking protein 5 (DOK5)-mediated mitogen-activated protein kinase (MAPK) signaling pathway. Chip retrieval and difference analysis were used for the potential mechanism of miR-141-3p on glaucoma. All modeled mice were transfected with different expression of mimic or inhibitor. The expressions of miR-141-3p, DOK5, and related genes and proteins of the MAPK signaling pathway were detected by Reverse transcription quantitative polymerase chain reaction and western blot analysis. Cell proliferation, lumen formation, and apoptosis in the retinal vascular epithelial cells and RGCs were detected using Matrigel angiogenesis and terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling assays. Moreover, a total of 63 and 294 differentially expressed genes were obtained in GSE2378 and GSE9944 chips, and 4 genes were within the intersection of the chips. In addition, the results showed that miR-141-3p was found to inhibit the DOK5 gene and activate the MAPK pathway. The number of RGCs, the expression of p38, extracellular-signal-regulated kinases (ERK), Jun N-terminal kinase (JNK), IGF-1, VEGF, HIF1-α, Bax, caspase-3, and the extent of p38, ERK, and JNK phosphorylated were decreased with miR-141-3p upregulation. Lastly, the results obtained showed that miR-141-3p inhibited the proliferation of retinal vascular epithelial cells and inhibited angiogenesis, as well as promoted apoptosis of RGCs. The study suggests that miR-141-3p inhibits retinal neovascularization in glaucoma mice by impeding the activation of the DOK5-mediated MAPK signaling pathway.
Publication
Journal: Nitric Oxide - Biology and Chemistry
February/8/2018
Abstract
OBJECTIVE
In previous studies, upregulation of NOS during acclimatization of rats to sustained hypobaric hypoxia was associated to cardioprotection, evaluated as an increased tolerance of myocardium to hypoxia/reoxygenation. The objective of the present work was to investigate the effect of acute hypobaric hypoxia and the role of endogenous NO concerning cardiac tolerance to hypoxia/reoxygenation under β-adrenergic stimulation.
METHODS
Rats were submitted to 58.7 kPa in a hypopressure chamber for 48 h whereas their normoxic controls remained at 101.3 kPa. By adding NOS substrate L-arg, or blocker L-NNA, isometric mechanical activity of papillary muscles isolated from left ventricle was evaluated at maximal or minimal production of NO, respectively, under β-adrenergic stimulation by isoproterenol, followed by 60/30 min of hypoxia/reoxygenation. Activities of NOS and cytochrome oxidase were evaluated by spectrophotometric methods and expression of HIF1-α and NOS isoforms by western blot. Eosin and hematoxiline staining were used for histological studies.
RESULTS
Cytosolic expression of HIF1-α, nNOS and eNOS, and NO production were higher in left ventricle of hypoxic rats. Mitochondrial cytochrome oxidase activity was decreased by hypobaric hypoxia and this effect was reversed by L-NNA. After H/R, recovery of developed tension in papillary muscles from normoxic rats was 51-60% (regardless NO modulation) while in hypobaric hypoxia was 70% ± 3 (L-arg) and 54% ± 1 (L-NNA). Other mechanical parameters showed similar results. Preserved histological architecture was observed only in L-arg papillary muscles of hypoxic rats.
CONCLUSIONS
Exposure of rats to hypobaric hypoxia for only 2 days increased NO synthesis leading to cardioprotection.
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Publication
Journal: Zhonghua gan zang bing za zhi = Zhonghua ganzangbing zazhi = Chinese journal of hepatology
April/21/2005
Abstract
OBJECTIVE
To investigate the effect of hypoxia on chronic alcoholic liver disease.
METHODS
Twenty four male Sprague-Dawley rats were randomly into two groups. The alcohol group (n=12) was fed 56% (v/v) of ethanol once per day by gastric infusion at 8 g/kg body weight for 24 weeks. The control group (n=12) was gastrically infused with normal saline with the same dose. At the end of 24 weeks, a blood sample was collected for determination of hepatic enzymes and then the rat was killed. Liver specimens were obtained for immunohistochemical staining and frozen at -80 degrees C used for RT-PCR.
RESULTS
Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity increased significantly compared to the control group. A significant elevation in the expression of HIF1-alpha in liver of alcohol group was found compared to the control group.
CONCLUSIONS
Hypoxia inducible factor 1-alpha expression was activated by ethanol-induced injury. This information suggested that hypoxia was involved in mechanism of alcoholic liver disease.
Publication
Journal: PLoS Neglected Tropical Diseases
May/22/2020
Abstract
We present a comprehensive analysis of the hepatic miRNA transcriptome at one month post-infection of experimental primary alveolar echinococcosis (AE), a parasitic infection caused upon ingestion of E. multilocularis eggs. Liver tissues were collected from infected and non-infected C57BL/6 mice, then small RNA libraries were prepared for next-generation sequencing (NGS). We conducted a Stem-loop RT-qPCR for validation of most dysregulated miRNAs. In infected mice, the expression levels of 28 miRNAs were significantly altered. Of these, 9 were up-regulated (fold change (FC) ≥ 1.5) and 19 were down-regulated (FC ≤ 0.66) as compared to the non-infected controls. In infected livers, mmu-miR-148a-3p and mmu-miR-101b-3p were 8- and 6-fold down-regulated, respectively, and the expression of mmu-miR-22-3p was reduced by 50%, compared to non-infected liver tissue. Conversely, significantly higher hepatic levels were noted for Mus musculus (mmu)-miR-21a-5p (FC = 2.3) and mmu-miR-122-5p (FC = 1.8). In addition, the relative mRNA expression levels of five genes (vegfa, mtor, hif1-α, fasn and acsl1) that were identified as targets of down-regulated miRNAs were significantly enhanced. All the five genes exhibited a higher expression level in livers of E. multilocularis infected mice compared to non-infected mice. Finally, we studied the issue related to functionally mature arm selection preference (5p and/or 3p) from the miRNA precursor and showed that 9 pre-miRNAs exhibited different arm selection preferences in normal versus infected liver tissues. In conclusion, this study provides first evidence that miRNAs are regulated early in primary murine AE. Our findings raise intriguing questions such as (i) how E. multilocularis affects hepatic miRNA expression;(ii) what are the alterations in miRNA expression patterns in more advanced AE-stages; and (iii) which hepatic cellular, metabolic and/or immunologic processes are modulated through altered miRNAs in AE. Thus, further research on the regulation of miRNAs during AE is needed, since miRNAs constitute an attractive potential option for development of novel therapeutic approaches against AE.
Publication
Journal: Medical Gas Research
April/7/2014
Abstract
Hyperbaric oxygen therapy (HBOT), a therapy that have patients breath in pure oxygen in a pressurized chamber, has been long used as a treatment for conditions such as decompression sickness and carbon monoxide poisoning. Oxygen recently has been found to be an important component in skin rejuvenation, treatment of photoaging skin, and improvement in skin complexions. The interest in the use of HBOT for this purpose is continually growing and becoming more widespread. In addition to aging and genetic makeup, chronic UV radiation due to everyday exposure, especially UV-B, can greatly increase the rate of wrinkle formation through increasing skin angiogenesis and degradation of extracellular matrix molecules. The use of HBOT and hyperoxia conditions has been found to attenuate the formation of wrinkles from UV irradiation. It accomplishes the task by possibly inhibiting various processes and pathways involved such as the HIF1-α, VEGF, neutrophil infiltrations, and MMP-2 & MMP-9, which are directly involved with promoting skin angiogenesis in its active state. There are currently medical aesthetic clinics that are using oxygen therapy under high pressure applied directly to skin to reduce visible wrinkles but this procedure is not widespread yet due to more research that needs to be done on this topic. However, this treatment for wrinkles is definitely growing due to recent studies done showing the effectiveness of oxygen therapy on wrinkles. This review article will explore and summarize researches done on possible mechanisms dealing with the use of oxygen therapy for reduction of UVB-caused wrinkles, its side effects, and its possible future improvement and use in medicine.
Publication
Journal: Current Opinion in Pharmacology
October/5/2020
Abstract
Hypoxia, metabolic activity, cell death and immune responses influence the adenosine concentrations in the extracellular space. Cellular responses to hypoxia and inflammation in myeloid cells promote activation of adenosine sensing circuit, which involves increased expression of ectoenzymes that converts phospho-nucleotides such as ATP to adenosine and increased expression of G protein-coupled adenosine receptors. Adenosine sensing circuitry also involves feedforward signaling, which leads to increased expression of hypoxia-inducible factor 1-alpha (HIF1 and feedback signaling, which leads to the suppression of inflammatory transcription factor, the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation. In this review we will discuss how different subsets of myeloid cells sense adenosine accumulation and how adenosine sensing by myeloid cells influence progression of different immune-related conditions including cancer.
Publication
Journal: Journal of Cancer Research and Therapeutics
October/23/2018
Abstract
UNASSIGNED
Epidermal growth factor-like domain-containing protein 7 (EGFL7) is an endothelial cell-derived secreted factor that regulates vascular tube formation. In human cancer, the specificity of expression is lost as EGFL7 has been detected in tumor cells, in addition to endothelial cells. This study evaluated the intricate relationship between hypoxia-inducible factor 1-alpha (HIF-1α) and EGFL7 under both hyperoxia and hypoxia states.
UNASSIGNED
In the present study, immunohistochemical staining and ELISA were applied to examine the relative level of EGFL7 in 182 cases of hepatocellular carcinoma (HCC) formalin-fixed and paraffin-embedded tissues and 110 cases of HCC serum samples. Quantitative polymerase chain reaction and Western blotting were applied to verify the correlation between serum EGFL7 level and anoxic microenvironment. Immunohistochemical staining was performed to determine the correlation between EGFL7 and HIF1-α.
UNASSIGNED
The correlations between EGFL7 expression and patients' age, tumor size, gender, N-stage, history of cirrhosis, M-stage, history of hepatitis C, and history of hepatitis B were statistically insignificant (P = 0.28, 0.34, 0.71, 0.15, 0.8, 0.2, 0.052, and 0.14, respectively). High level of EGFL7 was significantly correlated with overall survival as well as disease-free survival in 182 HCC patients (P = 0.0016 and P < 0.001, respectively). The correlations between serum EGFL7 and vascular invasion and extrahepatic metastasis were statistically significant (P < 0.0001). Among the 35 HIF1-α-positive HCC patients, 69% were medium positive and 31% were strong positive. EGFL7 protein expression level was oxygen dependent in HCC line (P < 0.05).
UNASSIGNED
EGFL7 was found to be a potential predictor for HCC survival and metastasis state; EGFL7 may be a promising biomarker and therapeutic target in human HCC.
Publication
Journal: eLife
July/18/2021
Abstract
The cellular adaptive response to hypoxia, mediated by high HIF1α levels includes metabolic reprogramming, restricted DNA replication and cell division. In contrast to healthy cells, the genome of cancer cells, and Kaposi's sarcoma associated herpesvirus (KSHV) infected cells maintains replication in hypoxia. We show that KSHV infection, despite promoting expression of HIF1α in normoxia, can also restrict transcriptional activity, and promoted its degradation in hypoxia. KSHV-encoded vCyclin, expressed in hypoxia, mediated HIF1α cytosolic translocation, and its degradation through a non-canonical lysosomal pathway. Attenuation of HIF1α levels by vCyclin allowed cells to bypass the block to DNA replication and cell proliferation in hypoxia. These results demonstrated that KSHV utilizes a unique strategy to balance HIF1α levels to overcome replication arrest and induction of the oncogenic phenotype, which are dependent on the levels of oxygen in the microenvironment.
Keywords: DNA replication; KSHV; hif1 alpha; infectious disease; lysosomal degradation; microbiology; vCyclin; virus.
Publication
Journal: Biomaterials Science
November/11/2021
Abstract
Epidermal growth factor receptor (EGFR) normally over-expresses in non-small cell lung cancer (NSCLC) cells. Its mutations act as oncogenic drivers in the cellular signal transduction pathway, and induce the downstream activation of numerous key cellular events involved in cellular proliferation and survival. EGFR tyrosine kinase inhibitors (EGFR-TK inhibitors), such as gefitinib and erlotinib, have been used for a long time in the treatment of NSCLC. However, they fail to overcome the EGFR-TK mutation due to the acquisition of drug resistance. It is strongly believed that the epithelial-to-mesenchymal transition (EMT) is a key player for acquired resistance and consequent limitation of the clinical efficiency of EGFR-TKIs. Therefore, a new strategy needs to be developed to overcome the resistance in NSCLC. In this current study, we have disclosed for the first time the efficiency of transferrin-modified PLGA-thymoquinone-nanoparticles in combination with gefitinib (NP-dual-1, NP-dual-2 and NP-dual-3) towards gefitinib-resistant A549 cells. The gefitinib-resistant A549 cells (A549/GR) showed 12.3-fold more resistance to gefitinib in comparison to non-resistant A549 cells. The phenotypic alteration resembling spindle-cell shape and increased pseudopodia integuments featured the EMT phenomena in A549/GR cells. EMT in A549/GR was later coupled with the loss of Ecad and expansion of Ncad, along with upregulated vimentin expression, as compared to the control A549 cells. Moreover, the invasive nature and migration potential are more amplified in A549/GR cells. Pre-incubation of A549 cells with TGFβ1 also initiated EMT, leading to drug resistance. Conversely, treatment of A549 or A549/GR cells with NP-dual-3 effectively retrieved the sensitivity to gefitinib, restricted the EMT phenomenon, and impaired the TGFβ1-induced EMT. On unveiling the underlying mechanism of therapeutic action, we found that STAT3 and miR-21 were individually overexpressed in the A549/GR cells by transfection, and followed by treatment with NP-dual-3. Simultaneously, NP-dual-3 fragmented HIF1-α induced EMT in A549/GR cells and reduced the CSCs markers, viz., Oct-4, Sox-2, Nanog, and Aldh1. These data are self-sufficient to suggest that NP-dual-3 re-sensitizes the drug-resistant A549/GR cells to gefitinib, possibly by retrieving MET phenomena via modulation of STAT3/mir-21/Akt/PTEN/HIF1-α axis. Thus, TQ nanoparticles combined with TKI gefitinib may provide an effective platform to treat NSCLC.
Publication
Journal: Nutricion Hospitalaria
March/14/2019
Abstract
Introduction: epigallocatechin-3-gallate (EGCG) is the most abundant catechin contained in green tea (Camellia sinensis) and has been associated with anti-obesity and anti-cancer effects, but the exact molecular mechanisms remain elusive. In this context, this study was designed to improve the understanding of the EGCG anti-obesity and anti-cancer action. Objectives: this study was designed to examine the effects of EGCG on the expression of genes involved in obesity and cancer pathways in the peripheral blood mononuclear cells of obese women. Material and methods: this longitudinal interventional study enrolled eleven women with severe obesity that were submitted to eight weeks of green tea (decaffeinated green tea capsules with 450.7 mg of EGCG, two capsules/day) supplementation (intervention group) and ten eutrophic women as a control group. Weight (kg), body mass index (BMI, kg/m2), fat mass (kg) and gene expression (qPCR method) were assessed before and after supplementation. HIF1-alpha (HIF1-α), phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) and rapamycin-insensitive companion of mTOR (RICTOR) were selected as potential targets. Results: after supplementation, body weight (114.9 ± 14.3 versus 115 ± 13.8 kg), body mass index (44.1 ± 3.7 versus 44.1 ± 3.9 kg/m2) and fat mass (47.6 ± 3.3 versus 47.3 ± 3.4 kg) did not change. EGCG upregulated the RICTOR and HIF1-α expression, however, did not modify PI3K expression. Conclusion: this study demonstrated that EGCG has a potential role to obesity and cancer related to obesity control and can be used not only for the purpose of weight loss, but also for the improvement of obesity-related comorbidities.
Publication
Journal: Neurological Research
January/4/2020
Abstract
Objectives: Cardiac glycosides are used as potential anti-cancer agents due to their effects on the inhibition of proliferation and induction of apoptosis and/or autophagy in cancer cells. Herein, we aimed to study the potential signaling pathways taken role in differential cell-death properties of AnvirzelTM which is consisted of two toxic cardiac glycosides (oleandrin and oleandrigenin), in U87 human glioblastoma cells.Methods: The anti-proliferative and anti-migratory effects of AnvirzelTM were assessed in U87 cells by WST-1 assay and wound healing assay, respectively. After treatment of AnvirzelTMwith doses of 10, 25, 50, 100 and 250 μg/ml, expression levels of proteins related to cell death were investigated by Western blot.Results: Anvirzel™ markedly inhibited the growth of U87 cells in a time- and dose-dependent manner following 24 h and 48 h treatments (p < 0.05). In addition, it was found that Anvirzel™ inhibited GSK-3, NOS and HIF1-α expressions whereas activated ERK in U87 cells compared to vehicle (p < 0.05).Discussion: The results suggested that AnvirzelTM regulated cell death distinctly from apoptosis in human glioblastoma cells. Further studies are required for validation of mechanistic insights about the potential signaling pathways taken role in differential cell death properties of AnvirzelTM.
Publication
Journal: Aging
February/22/2021
Abstract
We investigated the association between single nucleotide polymorphisms (SNPs) in the HIF1A gene and the prognosis of advanced non-small cell lung cancer (NSCLC) patients undergoing radiation therapy. Patient overall survival (OS) and progression-free survival (PFS) were analyzed. The rs11549465 TT genotype was associated with poor PFS (P<0.001) and OS (P=0.001). The rs2057482 TT genotype was also associated with poor PFS (P=0.002) and OS (P=0.007). Stratified analyses revealed that these associations occurred in patients with a smoking history, squamous cell carcinoma, and stage IIIA disease, as well as those receiving radiation therapy a radiation dose of ≥70 Gy. We found associations between SNPs and PFS but not OS in patients without a smoking history, other histological types, and stage IIIB disease, as well as those undergoing chemoradiotherapy with a radiation dose of <70 Gy. No associations were observed between rs11549467 or rs110873142 and NSCLC prognosis. These results suggest that HIF1A polymorphisms can be used as independent prognostic biomarkers for NSCLC patients receiving radiation therapy.
Keywords: gene polymorphisms; non-small cell lung cancer; prognosis; survival.
Publication
Journal: Chinese Journal of Lung Cancer
November/22/2015
Abstract
OBJECTIVE
The prognosis of malignant pleural effusion (MPE) was poor, injecting anti-angiogenesis agents in pleural cavity might be to reducing the volume of pleural effusion. The aim of this study is to investigate the therapeutical effect of pleural injection of recombinant human endostain, cisplatin and recombinant human endostain combined with cisplatin to MPE nude mice.
METHODS
MPE model was built by intrpleural injection of Lewis lung cancer cells (LCC) into BALB/c nude mice. Intrpleural injection of recombinant human endostain (E), cisplatin (P) and recombinant human endostain combined with cisplatin (EP) was performed, MPE volume was measured, immunohistochemistry of CD31 was carried out to calculate micro vessel density (MVD), angiogenesis and apoptosis gene expression was detected.
RESULTS
MPE volume was reduced by intrapleiral injection of recombinant human endostain and recombinant human endostain combined with cisplatin, MPE volume was positive correlated with MVD. Vescular epidermal growth factor-α (VEGF-α) expression reduced simultaneously with expression of hypoxia induced factor-1 (HIF1-α) elevated at the same time.
CONCLUSIONS
MPE model could be made by intrapleural injection of LLC. Intrapleural injection of recombinant human endostain could reduce MPE volume of nude mice. The potential molecular mechanism of the therapeutical effects of intapleural injection of recombiant endostatin might be related to the downregulation of VEGF-α expression and neovascularization. .
Publication
Journal: Oncology
April/28/2021
Abstract
Tumour angiogenesis is a crucial factor associated with tumour growth, progression, and metastasis. The whole process is the result of an interaction between a wide range of different molecules, influencing each other. Herein we summarize novel discoveries related to the less known angiogenic molecules such as galectins, pentraxin-3, Ral-interacting protein of 76 kDa (RLIP76), long non-coding RNAs (lncRNAs), B7-H3, and delta-like ligand-4 (DLL-4) and their role in the process of tumour angiogenesis. These molecules influence the most important molecular pathways involved in the formation of blood vessels in cancer, including the vascular endothelial growth factor (VEGF)-vascular endothelial growth factor receptor interaction (VEGFR), HIF1-a activation, or PI3K/Akt/mTOR and JAK-STAT signalling pathways. Increased expression of galectins, RLIP76, and B7H3 has been proven in several malignancies. Pentraxin-3, which appears to inhibit tumour angiogenesis, shows reduced expression in tumour tissues. Anti-angiogenic treatment based mainly on VEGF inhibition has proved to be of limited effectiveness, leading to the development of drug resistance. The newly discovered molecules are of great interest as a potential source of new anti-cancer therapies. Their role as targets for new drugs and as prognostic markers in neoplasms is discussed in this review.
<strong cl<em>a</em>ss="sub-title"> Keywords: </strong> <em>a</em>ngiogenesis; c<em>a</em>rcinogenesis; g<em>a</em>lectins.
Publication
Journal: Intensive Care Medicine Experimental
June/10/2021
Abstract
Background: The vascular endothelium has important endocrine and paracrine roles, particularly in the regulation of vascular tone and immune function, and it has been implicated in the pathophysiology of a range of cardiovascular and inflammatory conditions. This study uses a series of transgenic murine models to explore for the first time the role of the hypoxia-inducible factors, HIF-1α and HIF-2α in the pulmonary and systemic circulations as potential regulators of systemic vascular function in normoxic or hypoxic conditions and in response to inflammatory stress. We developed a series of transgenic mouse models, the HIF-1α Tie2Cre, deficient in HIF1-α in the systemic and pulmonary vascular endothelium and the L1Cre, a pulmonary endothelium specific knockout of HIF-1α or HIF-2α. In vivo, arterial blood pressure and metabolic activity were monitored continuously in normal atmospheric conditions and following an acute stimulus with hypoxia (10%) or lipopolysaccharide (LPS). Ex vivo, femoral artery reactivity was assessed using wire myography.
Results: Under normoxia, the HIF-1α Tie2Cre mouse had increased systolic and diastolic arterial pressure compared to litter mate controls over the day-night cycle under normal environmental conditions. VO2 and VCO2 were also increased. Femoral arteries displayed impaired endothelial relaxation in response to acetylcholine mediated by a reduction in the nitric oxide dependent portion of the response. HIF-1α L1Cre mice displayed a similar pattern of increased systemic blood pressure, metabolic rate and impaired vascular relaxation without features of pulmonary hypertension, polycythaemia or renal dysfunction under normal conditions. In response to acute hypoxia, deficiency of HIF-1α was associated with faster resolution of hypoxia-induced haemodynamic and metabolic compromise. In addition, systemic haemodynamics were less compromised by LPS treatment.
Conclusions: These data show that deficiency of HIF-1α in the systemic or pulmonary endothelium is associated with increased systemic blood pressure and metabolic rate, a pattern that persists in both normoxic conditions and in response to acute stress with potential implications for our understanding of the pathophysiology of vascular dysfunction in acute and chronic disease.
Keywords: Blood pressure; HIF-1α; HIF-2α; Haemodynamics; Metabolism; Vascular endothelium.
Publication
Journal: iScience
March/4/2021
Abstract
HIF1-alpha expression defines metabolic compartments in the developing heart, promoting glycolytic program in the compact myocardium and mitochondrial enrichment in the trabeculae. Nonetheless, its role in cardiogenesis is debated. To assess the importance of HIF1-alpha during heart development and the influence of glycolysis in ventricular chamber formation, herein we generated conditional knockout models of Hif1a in Nkx2.5 cardiac progenitors and cardiomyocytes. Deletion of Hif1a impairs embryonic glycolysis without influencing cardiomyocyte proliferation and results in increased mitochondrial number and transient activation of amino acid catabolism together with HIF2α and ATF4 upregulation by E12.5. Hif1a mutants display normal fatty acid oxidation program and do not show cardiac dysfunction in the adulthood. Our results demonstrate that cardiac HIF1 signaling and glycolysis are dispensable for mouse heart development and reveal the metabolic flexibility of the embryonic myocardium to consume amino acids, raising the potential use of alternative metabolic substrates as therapeutic interventions during ischemic events.
Keywords: Animal Physiology; Biological Sciences; Cellular Physiology; Developmental Biology.
Publication
Journal: mSystems
May/11/2021
Abstract
Oral epithelial cells monitor microbiome composition and initiate immune response upon dysbiosis, as in the case of Candida imbalances. Candida species, such as C. albicans and C. parapsilosis, are the most prevalent yeasts in the oral cavity. Comparison of healthy oral epithelial cell responses revealed that while C. albicans infection robustly activated inflammation cascades, C. parapsilosis primarily activated various inflammation-independent pathways. In posttranscriptional regulatory processes, several miRNAs were altered by both species. For C. parapsilosis, the dose of yeast cells directly correlated with changes in transcriptomic responses with higher fungal burdens inducing significantly different and broader changes. MicroRNAs (miRNAs) associated with carbohydrate metabolism-, hypoxia-, and vascular development-related responses dominated with C. parapsilosis infection, whereas C. albicans altered miRNAs linked to inflammatory responses. Subsequent analyses of hypoxia-inducible factor 1α (HIF1-α) and hepatic stellate cell (HSC) activation pathways predicted target genes through which miRNA-dependent regulation of yeast-specific functions may occur, which also supported the observed species-specific responses. Our findings suggest that C. parapsilosis is recognized as a commensal at low doses by the oral epithelium; however, increased fungal burden activates different pathways, some of which overlap with the inflammatory processes robustly induced by C. albicans IMPORTANCE A relatively new topic within the field of immunology involves the role of miRNAs in innate as well as adaptive immune response regulation. In recent years, posttranscriptional regulation of host-pathogenic fungal interactions through miRNAs was also suggested. Our study reveals that the distinct nature of human oral epithelial cell responses toward C. parapsilosis and C. albicans is possibly due to species-specific fine-tuning of host miRNA regulatory processes. The findings of this study also shed new light on the nature of early host cell transcriptional responses to the presence of C. parapsilosis and highlight the species' potential inflammation-independent host activation processes. These findings contribute to our better understanding of how miRNA deregulation at the oral immunological barrier, in noncanonical immune cells, may discriminate between fungal species, particularly Candida species with high or low pathogenic potential.
Keywords: Candida; host-pathogen interaction; miRNA regulation; oral epithelial cell.
Publication
Journal: PeerJ
June/10/2021
Abstract
Liver cancer is the second most common cause of cancer-induced deaths worldwide. Liver cirrhosis and cancer are a consequence of the abnormal angio-architecture formation of liver and formation of new blood vessels. This angiogenesis is driven by overexpression of hypoxia-inducible factor 1-alpha (Hif1-α) and vascular endothelial growth factor (VEGF). Apart from this, protein kinase B (Akt) is also impaired in liver cancer. Despite the advancement in conventional treatments, liver cancer remains largely incurable. Nowadays, the use of naturally occurring anticancer agents particularly flavonoids is subject to more attention due to their enhanced physicochemical properties. Therefore, this study underlines the use of a natural anticancer agent taxifolin in the treatment of liver cancer using hepatocellular carcinoma cell line HepG2 and Huh7. The aim of our study is to devise a natural and efficient solution for the disease prevalent in Pakistan. The study involved the assessment of binding of ligand taxifolin using molecular docking. The binding of taxifolin with the proteins (Hif1-α, VEGF and Akt) was calculated by docking using Vina and Chimera. Further evaluation was performed by cell viability assay (MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) Assay), colony formation assay, cell migration assay, DNA ladder assay and flow cytometry. To see whether taxifolin directly affected expression levels, analysis of gene expression of Hif1-α, VEGF and Akt was performed using real-time polymerase chain reaction (qPCR) and western blotting. In silico docking experiments revealed that these proteins showed favorable docking scores with taxifolin. Treatment with taxifolin resulted in the inhibition of the liver cancer growth and migration, and induced apoptosis in HepG2 and Huh7 cell lines at an inhibitory concentration (IC50) value of 0.15 µM and 0.22 µM, respectively. The expression of HIF1-α, VEGF and Akt was significantly reduced in a dose- dependent manner. The inhibitory effect of taxifolin on hepatic cells suggested its chemopreventive and therapeutic potential. The studied compound taxifolin exhibited pronounced pro-apoptotic and hepatoprotective potential. Our study has confirmed the pro-apoptotic potential of taxifolin in liver cancer cell lines and will pave a way to the use of taxifolin as a chemotherapeutic agent after its further validation on the animal models and humans based epidemiological studies.
Keywords: Akt; Hepatocellular carcinoma cell line HepG2; Hif1-α; IC50; Liver Cancer; Pro-apoptotic; Taxifolin; VEGF.
Publication
Journal: International Reviews of Immunology
June/14/2021
Abstract
MDSCs (myeloid-derived suppressor cells) are a population of immature and heterogeneous bone marrow cells with immunosuppressive functions, and they are mainly divided into two subgroups: granulocytic MDSCs (G-MDSCs) and monocytic MDSCs (M-MDSCs). Immunosuppression is the main and most important function of MDSCs, and they mainly exert an inhibitory effect through endoplasmic reticulum stress and some enzymes related to inhibitors, as well as some cytokines and other factors. In addition, MDSCs also interact with other immune cells, especially NK cells, DCs and Tregs, to participate in immune regulation. A large number of MDSCs are found during normal pregnancy. Combined with their immunosuppressive effects, these results suggest that MDSCs are likely to be closely related to maternal-fetal immune tolerance. This review mainly shows the interaction of MDSCs with other immune cells and the important role of MDSCs in maternal-fetal tolerance. The current research shows that MDSCs are mainly mediated by STAT3, HLA-G, CXCR2, Arg-1 and HIF1-α in immune regulation during pregnancy. Interpreting maternal-fetal tolerance from the perspective of MDSCs provides a special perspective for research on immune regulation and maternal-fetal tolerance of MDSCs to obtain a more comprehensive understanding of immune regulation and immune tolerance.
Keywords: Myeloid-derived suppressor cells; immune regulation; immune tolerance; maternal-fetal.
Publication
Journal: Oncogene
November/29/2021
Abstract
Hyperactivation of RAS/MAPK signaling is commonly observed in hepatocellular carcinoma (HCC). Gain-of-function mutations of canonical RAS genes, however, are rarely detected and it remains unclear how the activity of this pathway is turned on during hepatocarcinogenesis. We performed a comprehensive analysis of RAS superfamily genetic alterations across ten subfamilies, 152 members in 377 HCC patients from the Cancer Genome Atlas database. RIT1 (Ras-like without CAAX 1) was the most frequently altered RAS member amplified in 13% of the HCC cohort. Both genomic amplification and CREB-mediated transcriptional activation contributed to the elevated RIT1 expression, and its overexpression correlated with RAS/MAPK activation and poor prognosis. Then, we found that RIT1-induced angiogenesis via the MEK/ERK/EIF4E/HIF1-α/VEGFA axis. MAP3K11 and MAP3K12, in addition to CRAF, could mediate this process by binding to RIT1. Moreover, RIT1 increased the phosphorylation of p38 MAPK and AKT to promote cell survival under reactive oxygen species stress. Based on this mechanistic understanding, we treated RIT1-overexpressing HCC with combined regimen sorafenib plus AKT inhibitor, and achieved enhanced antitumor effects in vivo. Our study reveals RAS "orphan" member RIT1 as the most common genetic alteration of RAS family in HCC and combination of sorafenib with AKT inhibitor might be a promising treatment strategy for RIT1-overexpressing HCC.
Publication
Journal: Healthcare
December/23/2021
Abstract
Introduction: Oxygen is emerging as an important factor in the local regulation of bone remodeling. Some preclinical data suggest that hyperoxia may have deleterious effects on bone cells. However, its clinical relevance is unclear. Hence, we studied the effect of hyperbaric oxygen therapy (HBOT) on serum biomarkers reflecting the status of the Wnt and receptor activator of NF-κB ligand (RANKL) pathways, two core pathways for bone homeostasis.
Materials and methods: This was a prospective study of 20 patients undergoing HBOT (mean age 58 yrs., range 35-82 yrs.) because of complications of radiotherapy or chronic anal fissure. Patients were subjected to HBOT (100% oxygen; 2.4 atmospheres absolute for 90 min). The average number of HBOT sessions was 20 ± 5 (range 8-31). Serum hypoxia-inducible factor 1-α (HIF1-α), osteoprotegerin (OPG), RANKL, and the Wnt inhibitors sclerostin and dickkopf-1 (DKK1) were measured at baseline and after HBOT by using specific immunoassays.
Results: HIF-1α in eight patients with measurable serum levels increased from 0.084 (0.098) ng/mL at baseline to 0.146 (0.130) ng/mL after HBOT (p = 0.028). However, HBOT did not induce any significant changes in the serum levels of OPG, RANKL, sclerostin or DKK1. This was independent of the patients' diagnosis, either neoplasia or benign.
Conclusion: Despite the potential concerns about hyperoxia, we found no evidence that HBOT has any detrimental effect on bone homeostasis.
Keywords: DKK1; HIF-1α; RANKL; hyperbaric oxygen therapy; osteoprotegerin; sclerostin.
Publication
Journal: Journal of Personalized Medicine
December/23/2021
Abstract
Multiple myeloma (MM) is characterized by the accumulation of malignant plasma cells in the bone marrow. Despite novel therapies, MM still remains an incurable cancer and new strategies are needed. Increased expression of the transcription factor Sex-determining region Y-related high-mobility-group box transcription factor 4 (SOX4) has been correlated with tumor development and progression through a variety of distinct processes, including inhibition of apoptosis, increased cell invasion and metastasis, and induction and maintenance of cancer-initiating cells. The role of SOX4 in MM is largely unknown. Since SOX4 is a known target of miR-335, we used miR-335 to assess whether SOX4 modulation could promote apoptosis in MM cells. Using an MM cell model we show that miR-335 acts both on SOX4-related genes (AKT, PI3K) and hypoxia-inducible factor 1-alpha (Hif1-α). In addition, we show miR-335-laden extracellular vesicles induced in B cells (iEVs) are also effective in targeting SOX4, causing apoptosis. Collectively, we propose that miR-335-laden iEVs could be developed as a novel form of gene therapy in MM.
Keywords: SOX4; exosomes; gene therapy; miR-335; multiple myeloma (MM).
Publication
Journal: International Journal of Molecular Sciences
April/2/2021
Abstract
Preeclampsia (PE) is a pregnancy disorder associated with placental dysfunction and elevated fetal hemoglobin (HbF). Early in pregnancy the placenta harbors hematopoietic stem and progenitor cells (HSPCs) and is an extramedullary source of erythropoiesis. However, globin expression is not unique to erythroid cells and can be triggered by hypoxia. To investigate the role of the placenta in increasing globin levels previously reported in PE, flow cytometry, histological and immunostaining and in situ analyses were used on placenta samples and ex vivo explant cultures. Our results indicated that in PE pregnancies, placental HSPC homing and erythropoiesis were not affected. Non-erythroid alpha-globin mRNA and protein, but not gamma-globin, were detected in syncytiotrophoblasts and stroma of PE placenta samples. Similarly, alpha-globin protein and mRNA were upregulated in normal placenta explants cultured in hypoxia. The upregulation was independent of HIF1 and NRF2, the two main candidates of globin transcription in non-erythroid cells. Our study is the first to demonstrate alpha-globin mRNA expression in syncytiotrophoblasts in PE, induced by hypoxia. However, gamma-globin was only expressed in erythrocytes. We conclude that alpha-globin, but not HbF, is expressed in placental syncytiotrophoblasts in PE and may contribute to the pathology of the disease.
Keywords: erythropoiesis; non-erythroid globin; oxidative stress; placenta; preeclampsia; syncytiotrophoblast.
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